Go here first http://www.aphex.com/thermionics/index.html then click on "white papers" and then on "the RPA described". More info than you'll want to know. Page 5 has the guts of the schematic.
Talking about gear using starved-plates or other
ways of doing-a-tube, does anyone know more about the Aphex-'Tubessence' thing ? The description sounds kind of mysterious and some reviews of their gear even differed w.r.t. those units containing an actual tube or not...
circuit is a revolutionary new invention (patents pending) which imparts the sonic characteristics of tubes
without the extremely high voltages, heat, fragility and short life span of conventional tube circuitry. Aphex calls
You should get suspicious once they come to the part of
"..It has been discovered that microphonics are far less a problem with an RPA than with a conventional tube circuit.."
This is because stage gain comes mainly from the 2N5401 transistor, driving the standard push-pull output pair.
And I know of much easier ways of obtaining transistor stage gain.
Thanks for the responses, interesting to read
about what this Tubessence is actually about.
Don't really know what to think of it, not too
impressed either I guess (like you all weren't),
but since it's such a simple circuit it'd might
be interesting to breadboard it sometime.
I'm actually a bit surprised Aphex didn't provide
the THD-trim in some form as a front-panel control.
BTW, last time I looked I thought I didn't see
the 107 mic pre being mentioned anymore at
the Apex-site (pricelist). It gave me the impression
that Tubessence was perhaps better be forgotten,
but other gear using it (109-EQ & 661) is still there.
Yes, Aphex is still into "Tubessence". The 107 has been replaced with a more feature-filled (and more professional looking) 207.
Unlike many people I actually like the 107/207. True, they are not 'real' tube circuits, but I used to have a 107 and regularly got compliments on tracks I recorded through it. I definitely like it better than the Behringer or ART stuff, and for people who don't have a lot of cash, and aren't willing to DIY, it can be a much better alternative to the other stuff competing in that price range.
My current tube mic pre is a UA 2-610, which I love. The G9 is on the list after my SSL compressor, Pultec EQ, and 1176. I hope I'll like it enough to sell the UA and by more parts!!
Sometimes great sound is simply the result of an honest mistake.
Maybe you have a schematic of your 2-610????
I have a lots of others....
"The ear is the only judge of tonal balance."
Radio Designer's handbook(1953)
Unfortunately, no. UA doesn't include the schematics in the manual like Urei did. I'm sure somewhere out there there's a 610 schematic floating around, and, supposedly, the 2-610 is taken directly from that, but usually, this is not the case as manufacturers seem to change things (usually for cost reasons) but don't mention the changes in the marketing of the product.
This WOULD be a great DIY since I truly think the box sounds fabulous. I'm really wondering what the G9 sounds like???
Thanks for responding.
In your opinion, does it sound anywhere like 'tube' (whatever that exactly is...) or is the 107/207 just a solidstate mic pre with a gimmick ? (As the Behringers MIC2200/T1953/... seem to be)Yes, Aphex is still into "Tubessence". The 107 has been replaced with a more feature-filled (and more professional looking) 207.
Unlike many people I actually like the 107/207. True, they are not 'real' tube circuits, but I used to have a 107 and regularly got compliments on tracks I recorded through it. I definitely like it better than the Behringer or ART stuff,
I used to own one of the original 107's, but I found it too harsh and brittle sounding. Definitely more SS sounding than tube (and not really good SS at that).
I don't know what you consider "harsh" and "brittle" sound, but I truly don't see how those adjectives can accurately describe Aphex's 107/207. Mackie/Behringer mixer preamps, absolutely, but not the Aphex stuff (unless your normal signal path is a colorful tube mic, through a colorful tube preamp, through a colorful tube compressor (or two) through a colorful tube eq....)
Most 'tube' gear (meaning there's a tube SOMEWHERE in the signal path!) in the price range of the 107/207 tends to be lifeless and/or dull/cottony sounding, dark gear. Unfortunately, many people who have never been fortunate enough to use true, nice tube gear (Manley, UA, TELEFUNKEN, Teletronix, Tube-Tech, etc...) think this is what tubes should sound like.
I do not consider the Aphex 107/207 to sound like 'real' tube gear, but harsh and brittle it is not. True, it doesn't take the 'biggest' picture of the signal you're recording, but I'd definitely describe it as being on the smooth (not brittle) side of neutral. Yes, I'd say it sounds more SS than the sound we like tubes for, and its tone isn't as commanding as a V72/76 with their glorious transformers, but it is pleasant, and if I ever needed to go back to more cost-concious gear, and for some reason couldn't DIY my own, then I'd be happy to use the 107/207 again (though I DO NOT much care for the similarly priced Behringer, dbx, ART tube stuff).
I truly do not mean to offend, Old House Scott, and I hope you do not feel attacked. Black and white print may be just about the WORST way to post an opposing opinion politely :( , but my experience just does not bear out your description, and I feel strongly that Peter, and others, may want to hear another voice.
(Of course, Peter, you could always cut straight to the chase and build yourself a G9 :D )
Peace to all,