Welcome to RO Conrad!

Davedog has been singing the praises of your amps, must say I'm intrigued.

Three distinct inputs would be very useful, but the "Headroom" control sounds like an absolutely ingenious studio feature.

I hope I get a chance to try that out sometime!

I love the idea of the headroom and trim features for the studio. It would probably be useful live as well - there are a lot of quiet restaurant gigs around now.

So you finally signed up!

Guys please ask some serious tube technology questions as we dont want Conrad going to sleep...... :shock:

This feature on this amp is something you wont really believe until you hear it.

I like to crank this down to about 12-15 watts and open up the 'trim'. It does compress the amp but it doesnt 'darken' the sound. With the preamps set to a 'crunch' as well as a smooth rhythm sound on the the other setting, PLUS being able to switch between them and combine them, makes for a great pallette.

I havent had one at the house yet but I'm guessing that this thing will do serious high-gain amplification with extreme clarity.

Imagine, all you studio dogs, having an amp that you can set the sustain and COMPRESSION without lossy artifacts. Its done at the amp and as we all know.....source source source...

Hiya Conrad!

SO ask your tube technology questions. Heres the real deal to answer them. Ya know, Hows the preamp tubes hooked up? Power section choices? (a plethora of output tubes.....this one is EL34's but I've played on other Conrads with EL84's, 6V6's, 6L6's, KT66's....they all sound different) How the amps are gain staged?

BTW. Plank spankers especially...The input sensitivity and the response to single-coils is the thing you have always dreamed about.

Welcome to recording.org, Conrad!

Since Dave told me about your amps, then spending an evening checking out your website and listing to the audio clips, I have been drooling.

Your Echelon amp sounds really cool.

For those of you...

check out http://www.conradamps.com/

I don't know much about the tech side of amps but I definitely know what I like to hear. Dave, do you have an audio clip of this new design?

Conrad, Dave tells me your amps are all custom made, build personally by you in your shop. To me... this says quality control and a very personal touch of perfection.

Feel welcome to talk about your designs, how you build the cases ( Finger Jointed Pine Cabinetry) , leather finish too!

Check these specs on the Blues Jammer:

Tolex, Grill Cloth and Trim Options:

The amp comes stock with Cream Tolex, Oxblood Grill Cloth, Brown Piping and Brown Leather Handle. Other Options are Black Tolex with either Oxblood or Wheat Grill Cloth and brown piping. A third option is Brown Tolex, Wheat Grill Cloth, Brown Piping, Beige Trim and Brown Leather Handle.

Your Velvet Hammer's design is much different in style. Is there a reason for this?

Finally for this post:

Special Features:

1.*Aluminum Chassis with chassis mounted tube sockets
2.*Mono-Crystal “Super Wire” used throughout (20 Gauge - solid core) This is the finest copper wire on the planet. (Details)
3.*Hand-wired throughout on 1/8” Glass Epoxy circuit cards with eyelet and turret construction
4.*Circuits designed for the Blues Player
5.*Distributed filtering for low hum and noise
6.*Single-point star grounding scheme for low hum and noise
7.*Cathode biased
8.*No negative feedback
9.*Tube rectifier
10.*Finger Jointed Pine Cabinetry
11.*Heavy gauge Tolex

Could we ask you to talk about these points ( in detail, please please), why you use or do the things you do, that would be awesome!

There, how's that for a start? (y)

And please, if you have any audio clips of the Echelon, please share.

OK audiokid, I'm going to have to put you on "standby" because I'm taking a two-day break at the Oregon coast with my lovely wife. But, when I return, I'll get the tubes glowing and answer some of your questions. No clips yet of the Echelon amp but I'll take a gut shot picture so I can explain some of the details. Peace

Conrad

I was initially excited about the "Headroom" feature, but wanted to let those more experienced weigh in first.

My thoughts are:
Being more of a project studio, I often have to deal w/ guitarists that have crappy amps, feel their amps need to be cranked to 11 to get good "tone", or both.
I've been considering getting an amp or two for my studio as a result, and have been doing my homework here and elsewhere. Note - I don't have the budget to do this yet.

However, everything about this amp intrigues me. The different tone options between the Gain and Drive, EQ, Reverb - and then the added control of setting the wattage whilst still being able to saturate things w/ the Trim.

In summary, I've been hearing Dave's praises of your amps, and have been reluctant to spend the money on one boutique amp vs. a few tested standards. I still am.
But this thing really does sound like an engineer's dream - at least an engineer who doesn't have the dough to blow on a dozen different amps.

Sundhy wrote: The output stage is unique in that there is a "Headroom" control that sets the output wattage from 28 watts down to less than 1 watt - continuously variable.
Conrad Sundholm

This feature is actually not unique - there is a local guy to me - SW London - who has been building "boutique" amps for many many years with this feature.

His idea is to reproduce the "original" overdrive tone from many of the very old, limited power, valve amps when overdrive meant saturation of the valve output stage, not somewhere earlier as is now the norm. By varying the available power you can achieve this very distinct overdrive at various volumes and not just at the top end. In his circuit he actually reduces the bias to zero (0 Watts out) and effectively saves a standby switch!

I have two friends who play locally with these amps and get some really nice guitar tones with them. The idea certainly seems to add some flexibility to what they achieve.

EDIT: To add that this can be very useful in the studio too as playing levels can be well reduced while maintaining the high volume sound. Best mic'd though as I have tried to take an output from the output stage but there is no substitute for how this output stage interacts with the speaker..

Of course theres really 'nothing new' in terms of tube technology. The trick is to build something useful as well as musical and available. I'm sure there are similar designs floating about in someones lab somewhere in the world. I'm also certain there will some differences as its easy to arrive at the same place through differing paths with technology that is over 75 years old.

Cottage industry, consisting of boutique or custom built gear, is where the inductry is pointing to. While its cheaper to mass produce a design that can be assembled via automation, the personal touches and voicings that you can get through a custom built piece of gear far outweighs the sterile pablum from the other.

Next week, I'll have the new model amp, The Echelon, in my new room for a bit of a shake down cruise. It may make it out to a gig, but it will be tested to what it will do and how it does what it does.

If I can get the studio back up a little bit, enough to record some clips, I'll post them. If not I'll at least give my impressions.

Dave,

As a designer for over 30 years I realise what you are saying but I was trying to do two things, firstly point out that the amp's designer claimed a "unique" feature, which it is not. As Sundhy is presumably selling these he could get in hot water by making this claim. Just a warning really.

Secondly, I am unable to comment (as requested by the OP) directly on his particular amp but can comment on a similar design and its usefulness in the studio. I think I gave a little insight into how I found the power level control useful.

MrEase wrote: Dave,

As a designer for over 30 years I realise what you are saying but I was trying to do two things, firstly point out that the amp's designer claimed a "unique" feature, which it is not. As Sundhy is presumably selling these he could get in hot water by making this claim. Just a warning really.

Secondly, I am unable to comment (as requested by the OP) directly on his particular amp but can comment on a similar design and its usefulness in the studio. I think I gave a little insight into how I found the power level control useful.

I agree that certainly someone has thought of a feature like the one Conrad has described. The technology has been around for so long its inevitable.

That was my point.

He may have arrived at its function through a completely different way than what your acquaintence has done. Even though the results may be similar.

This is the beauty of old technology being wrung out for all its worth with modern applications.

My point being, do not assume that it ISNT unique in how its being implimented.

Conrad has been doing this a very long time.

Ever hear of Sunn Amplification? 'Sundholm' is the clue here.

Yes your point is well taken. Just dont assume the process is the same as the result.

He will enlighten on the process soon. Its quite interesting for all you DIY'ers and designers.

From someone who knows his way around vacuum tubes.

OK audiokid, I'll start down your list of the features found in the Conrad Amp line.

1. Aluminum Chassis - Since tubes and power transformers generate heat, the aluminum chassis acts as a heat sink to better dissipate heat to the air. Aluminum is certainly better than steel in this regard. Some amp manufacturers use aluminum because it is a better conductor for grounding purposes. If this is their claim then they are using random grounds throughout the chassis which could lead to ground loops and higher hum levels. I prefer to use a star grounding scheme where all grounds are starred at the input jack. The AC ground is at the other end of the chassis. All jacks are floating on the chassis with the exception of the input jack.

2. Mono-Crystal wire. - Mono Crystal wire (sometimes called Continuous Cast Copper) was developed by a Mr. Ohno in Japan. It is the process of drawing the wire that contributes to it purity and crystaline structure. Typical high quality Oxygen Free Copper wire has 500 crystal junctions in the metal every 10 meters. The Mono Crystal wire I use has .08 crystal junctions every 10 meters. The guitar signal must "negotiate" these junctions. Since there are far fewer crystal junctions in the Mono Crystal wire, the signal is purer with greater clarity and "quickness".

All internal wiring inside of each Conrad Amp utilizes this expensive superior wire. In addition, I use a copper content solder that insures that all connections with components and the Super Wire is copper. This way there are no dissimilar metals in the connection. In an earlier post DaveDog has commented that these amps do not "blur". This is because of the MonoCrystal wire. These amps are very quick and forward sounding.

There are 9 perfect Characteristics of Mono Crystal wire:

1.    Unidirectional
2.    Free of Impurity
3.    Flexibility
4.    Fatigue-Resistant
5.    Corrosive-Resistant
6.    Low Electric Resistance
7.    Non-Crystal Boundaries
8.    Rapid Transmissibility
9. Perfect in Structure 

Those all make Mono Crystal Wire an optimal material to be used for the internal wiring of a guitar amplifier. For the time being, Mono Crystal pure copper  has been considered the state-of-the-art conductor material in Hi-End  Audio cable industry. Yes, even superior to silver wire.

I think I will stop here and continue down audiokid's list in the near future.

Conrad

Conrad - In relative terms, how much does using mono-crystal wire add to the cost of an amp? I'm all for using high quality components, so features 2,3,4,5 make it worth paying a bit more for good wire. But I have to say that if the other claims are true, I'm going to have to change a chapter or two in the book I'm writing on partial differential equations. In fact, if you have a wire that conducts a signal faster than the speed of light, you are wasting your time making amps. You can make a time machine.

Of course, that is a joke. I'm well aware that the effective wave speed of electromagnetic waves is different in different media. But we are talking about speeds on the order of magnitude of the speed of light in a vacuum over a distance of a few feet. Not an easily measurable (much less audible) time lag.

Since the crystal structure of copper is face centered cubic, I would expect a long mono-crystal should have greater bi-directional symmetry than a multi-crystalline structure. So I'm very skeptical about the unidirectional claim.

Low crystal boundaries and lower resistance I would expect to be true, but as with the argument about silver wire: how is this better than thicker standard wire?

Again, if you like working with the wire and feel it is the best product you can get, that's fine. The best reason to pay for a handmade amp is because you trust the ears and judgment of the builder. In the end it is the sound of the amp that matters. Scientific arguments (even ones that are easier to verify than these) don't carry much weight.

Hey Bob, when it comes to wire there are skeptics, especially those with engineering degrees. My intention here is not to engage in a back and forth discussion of differing opinions but share my experience with using this wire.

I have successfully used the Mono Crystal wire in the recording studio as well as in the amps I build. My son Steve is the head engineer at Nightbird Recording Studios in Hollywood. (http://www.nightbirdrecordingstudio.com)

Together we have built custom mic pre's with this wire. In addition we have stripped the wire out of Manely mics and replaced it with the mono crystal wire to improve the performance. We have made Litz braided speaker cables with this wire. He has rewired the entire studio including the patch bay with this wire. We have also constructed mic cable with mono crystal wire - all with highly successful results. All I can tell you is that the midrange clarity and extended response in the studio is superb. This is what led me to use this wire in the Conrad amps.

Despite all the differences in technical opinion the proof is in the tone and the feel of the amp. Ask anyone who owns one.

The cost of the wire does run up the price of the amp somewhat because of the cost of the raw wire and the labor required to use this wire. However, the major cost of any guitar amp are the transformers, chassis tubes, speakers and labor.

OK, dialing down the output power is cool, but when you do THAT, aren't you failing to sufficiently saturate the output transformer to the same degree that the higher output power would be doing that? I was always under the impression that the output tranny was/is key to the coloration of the tone as it got whalloped by the tubes...acting as a kind of lowpass filter. Maybe that was "old school" ?

Moon, I'm no expert on what goes on inside there but I do understand the concepts inherant to sound reproduction and the effect that transformers have on the overall sound.

Conrad will have to address the technical side of this, but when you operate the amp in the manner you're talking about, not only do you NOT lose the high-end or the 'feeling' of the gain to the output, but you get this great compression. However its not the type of compression that has that little delay while the circuit grabs hold of the signal and then compresses it. It is now and immediate and quite unlike anything I have ever played through. Plus theres not that 'release' bloom.

I want to comment just a moment on the wire.

Understand that I am not a proponent of witchcraft or voodoo special cable claims that are the norm these days. I have operated on the fact that if it passes signal and does it without noise then its 'good' cable. Also realize that I am an Electrician with over 30 years of experience and have seen all sorts of wire especially high-tech cables used in computer suite construction and specialty equipment.

So. I have tried the M*^%ster cable, and several other oxygen free, special insulated low impedance blahblah blah etc etc wire and cables and have NOT noticed a difference from the good old Belden you can buy at a tenth the cost of these other magic wire thingys.

Of course this is an argument that takes up most of some peoples lives on other audiofile type sites and encites a riot whenever its mentioned in certain circles.

I can hear the critique now.....your testing parameters arent up to par...(okay, U87,Genelecs,EQ switched out)...You have faulty ears...(no doubt)

But heres my point. Conrad gave me a mic cable to dink with a few months back. Of the wire he has mentioned. Its WAY too stiff to make a good cable to lay-out on a setup but other than that, its the only cable I have ever heard a noticable difference in response from my trusty Beldens and etc's.. And its not a whole lot. But in a studio with this stuff in the walls and lots and lots of tracks going, there would be enough difference to make a difference.

And these amps responds quicker than any I have owned or played on. So........maybe theres a reason.

I'm, just sayin...............

moonbaby wrote: OK, dialing down the output power is cool, but when you do THAT, aren't you failing to sufficiently saturate the output transformer to the same degree that the higher output power would be doing that? I was always under the impression that the output tranny was/is key to the coloration of the tone as it got whalloped by the tubes...acting as a kind of lowpass filter. Maybe that was "old school" ?

Well as a designer, I would avoid any saturation of the output transformer like the plague! When a transformer core reaches magnetic saturation the inductance drops alarmingly and would seriously overload the output valves leading to premature failure (the cathodes would get stripped very easily - transistors would just pop!). Normally output transformers are generously rated because of this. Output stage saturation normally refers to the valves running out of either grid drive or anode voltage and it is this that leads to the "valve" overdrive sound. Reducing anode voltage or limiting grid drive both lead to overdrive conditions and it is these that I presume Sundhy is doing in these new amps.

EDIT: That is not to say that the design of the output transformer will not affect the sound. Also conventional transformers approach saturation more gently (shall we say) than a toroid. Saturation in both cases though is still to be avoided unless you really like the sound and are happy to keep buying output valves!

I believe ya!
I have heard the other amps on Conrads' site, awesome tone, awesome player (THAT certainly helps, doesn't it...LOL!).
BTW, I have a Supro 1624T that has these power tubes- 6973's- the same thing that they used in Wurlitzer juke boxes. Crank the amp and it grabs the note and "blooms" just like what you described...albeit at a bit louder volume levels:) I'll have to check out that Echelon...Tell Conrad to let go of his pretty wife long enough to post some new pix and clips!!!

Moonbaby, you are right about core saturation in the output tranny contributing to the tone of the amp. Output transformer core saturation occurs earlier in the lower frequencies. Out of curiosity I put the Echelon amp on the bench and ran some tests at full power and about 1/4 power. Here are the results:

Core saturation of the output transformer on this amp starts at about 150Hz and increases as I went down in frequency to 40Hz. The trim control on this amp determines the signal voltage swing into the phase inverter. I was able to create core saturation at 1/4th power by advancing the Trim Control.

Therefore Output Transformer core saturation can be achieved with this amp even at the lower "Headroom" settings. Thus the tone is preserved.

Conrad

Thanks, Moodbay for the question.

Conrad

There are some video clips of the amps on YouTube.

Go to http://www.youtube.com/conradamps

Here you find the Conrad Blues Jammer amp and the Conrad Velvet Hammer.

Sundhy wrote: Moonbaby, you are right about core saturation in the output tranny contributing to the tone of the amp. Output transformer core saturation occurs earlier in the lower frequencies. Out of curiosity I put the Echelon amp on the bench and ran some tests at full power and about 1/4 power. Here are the results:

Core saturation of the output transformer on this amp starts at about 150Hz and increases as I went down in frequency to 40Hz. The trim control on this amp determines the signal voltage swing into the phase inverter. I was able to create core saturation at 1/4th power by advancing the Trim Control.

Therefore Output Transformer core saturation can be achieved with this amp even at the lower "Headroom" settings. Thus the tone is preserved.

Conrad

Thanks, Moodbay for the question.

Conrad

With due respect I don't think we are talking about core saturation here but a drop in anode load impedance at low frequencies caused by limited primary inductance of the output transformer and this is independent of power level. Like I said earlier, magnetic saturation of the transformer core is to be avoided like the plague. True core saturation could never be maintained at the lower power levels as lower power inherently lowers the magnetic flux in the core. I do agree though that you should be able to maintain the "sound" with the lower power levels!

OK audiokid lets talk about # 5 on your list - Distributive Filtering:

In the gut shot picture attached you will notice that each filter capacitor in the power supply (blue) are located right at each tube it supplies. In the case of the single pre-amp tube notice that there is a separate power supply capacitor for each half of the dual triode. Also notice that the ground side of the capacitor is tied directly to the cathode circuit and the positive terminal of the cap is tied directly to the plate resistors. This is a very efficient way of filtering each node in the power supply. This approach also lowers hum and noise.

You will also note the filter capacitors on the right end of the board are larger and they become progressively smaller as you move down the board toward the pre-amp section. If large value capacitors are used throughout, the total capacitance is too high and the amp feels to stiff or tight. There are many factors that contribute to the feel of the amp - this is only one.

Now lets talk about the single point or star grounding scheme. Notice the green wires. They are the ground wires. As you can see, the first triode or pre-amp tube has its own ground bus (very short) and the green wire runs over to the input jack. There are a number of green wires going to the input jack - each from a separate stage on the wiring board. The result is a single ground point for all the circuit grounds - the input jack. All other jacks on the amp are lifted from the chassis and therefore are not grounded to the chassis. There is one other ground point on the chassis and that is the A.C. power cord ground which is located at the far end of the chassis - away from the single point circuit ground.

I'm not sure how to post an image here. You can see the photo at:

(Dead Link Removed)

Hi Conrad,

many of us are not facebook users, meaning, we can't see this image if we aren't signed up to Facebook.

To add images, its simple. bypass the quick replybox all together and hit

button.

The Quick Reply box is missing the extra option like img / bold/ youtube/ quote/ code/ list etc in post features. Its just a quick reply for text.
The official posting box has the full deal. (note) you get this in the edit mode as well)

Once there...

In the text box

copy the url of an image in the box below

highlight the full url string

like this

and click the img icon tag (above the box) and it will add the tags to make the image show on the forums. Once finished with your reply, Submit.

The image will show.

MrEase wrote: [quote=Sundhy]Moonbaby, you are right about core saturation in the output tranny contributing to the tone of the amp. Output transformer core saturation occurs earlier in the lower frequencies. Out of curiosity I put the Echelon amp on the bench and ran some tests at full power and about 1/4 power. Here are the results:

Core saturation of the output transformer on this amp starts at about 150Hz and increases as I went down in frequency to 40Hz. The trim control on this amp determines the signal voltage swing into the phase inverter. I was able to create core saturation at 1/4th power by advancing the Trim Control.

Therefore Output Transformer core saturation can be achieved with this amp even at the lower "Headroom" settings. Thus the tone is preserved.

Conrad

Thanks, Moodbay for the question.

Conrad

With due respect I don't think we are talking about core saturation here but a drop in anode load impedance at low frequencies caused by limited primary inductance of the output transformer and this is independent of power level. Like I said earlier, magnetic saturation of the transformer core is to be avoided like the plague. True core saturation could never be maintained at the lower power levels as lower power inherently lowers the magnetic flux in the core. I do agree though that you should be able to maintain the "sound" with the lower power levels!

First up I want to make it absolutely clear that I am not trying to decry Conrad's designs and do appreciate what he has added with this latest design. I was hoping that perhaps Conrad would acknowledge these earlier comments regarding core saturation but as he has not as yet, I felt that some further explanation would help in order to avoid any possible misunderstanding and also as some of you seem to have an interest in how these things work. I have tried to write this in a non technical fashion as much as possible - please let me know if I have failed!

Core saturation refers, unambiguously, to magnetic flux saturation in the output transformer magnetic core. It is this flux that transfers the energy between the primary and secondary circuits and saturation refers to the point when the magnetic flux in the core cannot increase any further. The transition between normal transformer action and saturation depends on the transformer construction and the consistency of the magnetic circuit. For a toroidal transformer the transition is much sharper than for the "conventional" output transformer using E and I cores. This is because the toroid has a completely consistent magnetic path with no right angles or changes in cross sectional area. It is inconsistencies in the magnetic path that slightly soften the transition as some of the magnetic flux leaks in to the air (just like a permanent bar magnet) and as the core approaches saturation these "leaks" increase thus softening the transition to saturation. This is why I doubt you would ever see a toroid in an output stage - conventional construction allows a small amount of leeway in terms of aggression on the valves and also other possibilities (see the side note below).

As I said before, saturation is to be avoided, but I will now try to explain why. When the primary winding current (i.e. output level) exceeds the point where saturation occurs two key things happen. Firstly the link between primary and secondary is lost. This is because any further increase in current does not cause increased magnetism and it is that magnetism that produces the secondary current - no more magnetism = no more secondary current - so the output no longer follows the input. Secondly and more dangerously for the valves is that the primary inductance drops alarmingly (almost to zero) as there is no longer an effective magnetic core for the primary inductance. This has a double impact for the valve, the first is that current will increase rapidly to the maximum the valve can provide and secondly, due to the lack of anode impedance, the anode voltage will track rapidly up to the supply voltage. These two simultaneous events on the anode are what leads to "stripping" of the cathode, which is where the coatings on the indirectly heated cathode literally get "sucked" off, leaving the valve with progressively lower emission and premature failure. So core saturation is generally not good all round either from the sonic point of view or reliability.

(Side note: At high frequencies (not necessarily in the audio band) another coupling mechanism (i.e. capacitance) also comes into play. That is not important for this explanation but can contribute significantly to the different "sound" of various transformers.)

What this also means is that when core saturation occurs the output will always be at the same level (for any particular frequency) - as it is only the magnetism that creates the output. This is why Conrads assertion in the last paragraph of the quoted post is simply wrong. If the output is running at 1/4 power there must be a consequent drop in the core magnetisation (otherwise the power level has not changed) and therefore the core cannot possibly be in saturation.

What I am convinced of is that Conrad has actually measured the "output stage saturation" which is indicated in his comments about frequency. As frequency lowers, the impedance of the primary circuit drops. The amount of this drop will depend on the primary inductance, the transformer ratio, and the load (speaker) impedance. At lower frequencies it is perfectly possible (and very common) for the valve and its drive level to "saturate" and be unable to provide further current, thus limiting the voltage swing at the anode and thus clipping the output. This is the classic valve overdrive sound of yesteryear where it was only the output stage that would distort as no-one had ever thought of deliberately overdriving earlier stages. It in no way implies that the transformer core is ever saturated.

This is exactly the sound that it seems to me that Conrad has achieved but at lower power levels. His circuit goes further than that in that he also allows you to vary the drive to the output stage which to me is a clear clue as to what is really happening. I'm sure it will sound great but really it has nothing at all to do with "core saturation".

I hope this helps those who may have been interested and stuck it through to the end!

A very interesting point from the engineers POV.

So your main 'gripe' is the use of language out of context.??

Hopefully this will clear the air. I'm sure that Conrad has not intended to misrepresent his designs in any way. He has been designing tube amps for a very very long time and has been successful at it. Not just as a boutique design/build shop either. There were a lot of highly successful bands in Britain that used his designs for many years. Lots of Sunn Bass and Guitar amps floating about.

Its very exciting for those of us who have wanted something that operates like this latest one. The very point of the 'old skool' overdrive in the output section rather than the thin reedy sound of preamp distortion AND at levels that are controllable down to a whisper, is something that has been virtually unavailable for those that like that sound.

Its a question that gets asked on here a lot, referring to "How do they get that guitar sound??" and using a recording where the obvious answer is a large amp in a controlled space turned up to get that output tube warmth and speaker distortion. Much like the Marshalls of yesteryear JTM's, Bluesbreakers and the like. Also the Fenders of old, Bassman, Supers, Vibrolux, etc. They all sound great but not till you get them in that 'sag' situation where there is no more gain to be had, only powersection sag and distortion.

Conrad has achieved this without the loss of the clarity. Or the 'feel' of the preamps sensitivity. The amp remains 'quick' even though it has the sound of the sag and the subsequent compressed feeling that comes with that.

My suggestion to you, MrEase, is simply email Conrad. His contact information is readily available and I'm sure he would talk shop with you about anything you desire to discuss. What I dont want is to have it appear to be running down of something that is simply a difference in terminology.

Your explanation of transformer logic was spot on and very interesting. Addressing Conrad in an email will net better results than doing so publically. He is certainly not an beginner and will see your points.

Well Dave, I thought I made it quite clear in my very first sentence that there is no "gripe" with Conrad or anyone here.

As far as contacting Conrad direct, I do not really see the point. I saw something I knew to be incorrect on a public forum so I don't see the point in correcting it privately and leaving the error in the public domain. That does not mean I am having a go at anyone nor making any comment on their experience however we all make mistakes and I do not like to see misleading information in what I regard as a quality forum.

What I commented on is neither ambiguous nor anything to do with language or semantics. Core saturation is VERY specific and was directly questioned by Moonbaby. What I believe Conrad responded to was output stage saturation which is a very different beast. At that stage I had already responded to Moonbaby's question so I was quite surprised to see Conrad's later response which was at odd's with what I had already posted and which I found to be referring to another phenomenum altogether.

Of course if you prefer me to respond privately and see errors stand on the forum then please let me know and I will not bother in the future! This is not trying to be awkward but is a direct response to the points you have raised.

I personally don't think that would do anything positive for the quality of this forum though. You are the mod here, you decide!

wow, Interesting topic.

I don't understand much on the theory side of this but I do know things don't have to make sense to sound good. I think at this point we might be suggesting Conrad disclose his design secrets. I really think we should ease and move on.

I look forward to hearing what the users are hearing, and hearing more on the different amps, designs, speakers, and how he builds these gems.

Good idea, BT. Besides, my comment ws probably mis-spoken in that I never intended it to be CORE saturation of the tranny, but simply saturation of the output stage (with the tranny acting as a LP filter). At least that is how things were explained to me by the engineers at Yamaha many years ago when they were developing their line of "transistorized-but-we-make-them-sound-like-tube-amps" in the late 70's. Guess what...they didn't !!!

Can I just explain that is certainly not my intention for Conrad to reveal any of his design secrets. All I have been trying to clarify is that when running a transformer at reduced power, saturation of the core is never going to happen. He was very specific in his earlier conclusion and I am confident that on reflection he would agree with the points I raised.

This is not intended in any way to be a comment on the performance of his Echelon design. This is something I thought I had made clear in my first post on this thread. Having heard and used a different amp that also reduces available power I can confirm that the overdrive at lower levels is equally lush and powerful as that at full power. This characteristic sound that we all seem to love arises from output stage saturation though and certainly not from output transformer core saturation.

I only took this up as I far too often see such simple mistakes bloom into urban myth! I think it is unfortunate that Conrad has not been back here lately as I'm sure that this could have been acknowledged and nippped in the bud very easily. Sadly instead of this Dave seemed to think I was having a gripe and decrying Conrad's design (which I had taken care to point out was not the case) and he also made a false assumption that it was a case of alternative terminologies -which it definitely isn't.

I have explained my position very carefully and clearly in PM's to you, Mr.Ease.

My take is not an assumption as much as a suggestion of misinterpretation of technical forms as was laid out by Moon in his last post.

I appreciate your willingness to keep the airwaves clear of assumptions and half-truths. It is something we strive for here and have done a good job with over the years. Its good that someone also cares deeply about these things.

MrEase, you are right concerning core saturation of the output transformer. I have been able to create it on the bench and have observed it on the scope. I believe it is possible that some players get into this region with their hot pickups and running an amp beyond its limits.

Sundhy, post: 300667 wrote: MrEase, you are right concerning core saturation of the output transformer. I have been able to create it on the bench and have observed it on the scope. I believe it is possible that some players get into this region with their hot pickups and running an amp beyond its limits.

Hi Conrad,

Thanks for responding - I haven't looked here for a while!

From that I presume you agree that core saturation cannot be achieved when the power level is backed off and all that lovely sound comes from saturating the output stage rather than the transformer! :<)

Yes that is right.