you're very right on with your assesment. the 737 experience for me was very similar. I own 2 RNC (one with the RNP) and the other I use with the Great River ME-1NV. (I will be adding the Speck ASC EQ or the upcoming G.R. EQ) but both chains i described gave me much better results than the over hyped 737..

the pre section was cool and the EQ was stellar, but the Compressor (like with most all in one channel strips) was very heavy, no transparacy, and too squashing. I also did experience 6 hour plus sessions heating up the Avalon and sounding mushier than when I started. i would even turn it off to cool it down (not sure if that helps, but it goes to show you that i noticed something different was going on).

if I was too spend that kind of cash for a single channel strip I would look at spending a few more bucks on a few others.

I did demo the Speck 5.0 before getting my ME-1NV and that pre was killer. it will be my next single channel pre (I just liked the ME color a bit more for my vocals)..you have a great chain! I would never switch out the Specks/RNC for the 737...Never! :D

nick,
The Speck 5.0 MicPre is hard to beat. Just look at the comparisons I ran. Most prefered the Speck to the Millennea and the Neve/Amek 9098! That says something. Actually I am not at all surprised at your obsevation... Kurt

Bobby and Kurt-

Thanks for the input! I trust my instincts, but it's nice to know they're (not necessarily) *crazy* instincts.

I was seriously considering the Great River. It was several $C's too much for my budget, but it was awesome.

best-
.nick

Nick - Do you know how many hours the 737's tubes have on them? That might be playing a bit of a role in your assements. My 737's compressor is quite useful for vocals (which is what I mainly use it for). I have a couple of RNCs, too, but I still prefer the 737 for the vocal work that we do here.

Bobby is correct on the temp of the 737, though. I find that after a long mix session there is more distortion from the 737 than there was at first. I always turn it off before I take a lunch break, etc., just to help keep it cool.

Aaron--
Can't say that I know that. Didn't the original 737 have a tube life indicator on it...somewhere?

I can't seem to find one on this.

Thanks-
.nick

It would seem to be a desirable thing for a mic pre’s sound to remain stable after it has been burned in and warmed up. For a pre to change its tone over the period of a session, is not a good thing. Are you sure you are allowing the pre to get enough ventilation? Tube gear usually needs a space above and below it in the rack. My Manly El OP manual recommends this.. as a matter of fact, so does the manual on my Amek/Neve 9098's and they are solid state.. Kurt

This is off Avalon's website:

" Tube Life
Q: How often will I need to change the tubes in my Vt-737sp / Vt-747sp?
A: The tubes in your 737sp are designed to operate for a minimum of 5,000 hours. We have seen units with tubes that have over 15,000 hours and are still operating within spec.
The way to tell if tubes are bad or failing:
1. Electronic Noise: All types from consistent high levels of hiss to random splats, static sounds and popcorn noise.
2. Microphonic Noise: To test for microphonic noise, simply tap the tube carefully with the rubber eraser at the end of a pencil. If you hear a loud ping or lasting ringing sound, the tube should be replaced. "

.nick

Originally posted by Kurt Foster:
Are you sure you are allowing the pre to get enough ventilation? Tube gear usually needs a space above and below it in the rack.

Actually Yes...I had the 737 out on its own due to the heat issues! (plenty of ventilation)....I have heard many users complain about the Mushy/dark/distorted (whatever you want to call it sound) once the unit was in use for a long period of time..

Originally posted by Bobby Loux:
Actually Yes...I had the 737 out on its own due to the heat issues! (plenty of ventilation)....I have heard many users complain about the Mushy/dark/distorted (whatever you want to call it sound) once the unit was in use for a long period of time..

Wow! That is very interesting. I would send Avalon an email and ask them about this.. See what they have to say about it. Tell them about RO, email this page to them.. This is something thay should address. That is supposed to be high end gear.

I bought my VT737SP used as well.

What I noticed with mine was that the micpre gain reduces by a few dB once the unit warms up thoroughly. To me, it was more of a gain change issue than a tonal change issue.

Anyways, I tried changing out the tubes to see if it would make any difference. And the symptom seems to have gnoe away. Well, at least it's not so obvious anymore.

The original tubes tested good on my tube tester, but the conductance reading was noticeably lower than two other brands I tried. My tester didn't think the original tubes were tired at all so I believe everything was working within spec. I ended up going with the ones I thought sounded best.

So far, I think I'm happy with the results.

Note that I didn't take any measurements before/after with my vt737sp, nor have I done any A/B testing so my observations with vt737sp's performances are highly subjective. When/if I have the time, I may very well go back and take measurements with an SG and DMM. I believe in my ears but I also know they can be fooled easily.

YMMV. And I'm very curious to find if anyone has seen and tried anything similar, or what Avalon has to say.

Disclaimer: I stock quite a few tubes and I do sell them now and then, including the 6922 used in VT737SP (and VT747 and Rode NTK etc etc). The above isn't intended as a SPAM, but since I used the tubes from my stock, I didn't want people to think I'm peddling them by listing the brands and claiming one better than another, or how it fixes some problem.

-- Call me paranoid, but I've seen enough of the anti-SPAM bickering at the 'other' board and I want no part of it. --

So I left out the brand names. If you want to know further details, please PM or email me.

I always keep a space on each side of tube gear and put a vented spacer in between. I had a 737 years ago and really liked it. I then sold it because people were not saying great things about it compared to a bunch of other pre's on the market and I couldn't afford to keep it and buy others. I have since bought a used (for cheap) just for the eq which I missed. Then I tried a vocal through it just to show myself that the preamp wasn't as good as the others I was using at the time. Damn if the 737 wasn't my favorite of the lot. My new favorite was the Phoenix which I prefered over the Great River NV for vocals (still a killer unit though) and the Vipre among other (Vintech etc.). It isn't the most transparent and not the most colored it just works perfect for my voice and my mic (Lawson L47MP), and the eq is still great, and the compressor still leaves somthing to be desired.