I owned this unit some years ago. I had a problem that the bottom half of the recorded wave form was severely 'rounded' or clipped, but not the top half. Wasn't DC offset, maybe a tube bias problem. This caused a muddy distortion in the sound. Record something and check the waveform before you buy. I also own the sister unit to this, a VCS-1 and it is gorgeous, does not have the above problem. You'd have a hard time getting it from me! It is a gate, compressor and limiter tube unit.

I had problems with the sound of mine- they came with russian tubes. I think they were going for a more guitar oriented market at the time as opposed to a more utilitarian pre. Don't know- just Guessing being digitech and all. This was in the early 90's and my boss bought this box. None of us really knew what to do with it in the music store back then, so we put it in the recording session. People back then were just starting to get into digital and ADATS were 3700 bucks!!!! I ended up buying it cause I thought it sounded great into an ADAT *and still do! but back then most of our customers weren't hip to high end preamps. Now it's a different story.

I swapped out the 12AX7A's with some Phillips and Telefunkens- big difference for the better, cleaned up the mud- I can drive the pre gain stage harder without the signal breaking up (it warms up and stays much tighter now).

I love mine. Made in canada- phase reverse, switchble phantom, inserts, nice eq, VU meters, digtal converter at 18 bits 48K (don't use mine)... I run it alongside my focusrite ISA 428 (use the converters in that)

You can get these for a song now too. Hell I paid 800 for mine. They are a good box for cheap. If you get one and it sounds muddy, just swap out the tubes.

PEACE

Mine is (NOS) unit from local dealer. Never power up for more than 8 or 10 years. When I burn in for 3 or 4 hr. They act weired....
The In - put of Ch.1 seems to come and go. If I hit the signal real hard the VU move and signal will print to Nuendo but sometimes it's not working. May be some cap was dead. Is it possible that the electronic component that never let electrical signal pass through for more than 8 or 9 years will be dead? Any tips?
By the way... anybody know how where to download service manual?
Thanks

The service manual that came with mine was actually copied from digitech- really cheaply. Basically the contracted company *ISA electronics or something like that- I'll have to check* just copied a few pages and stuck them in the box!

Sounds like a bad tube. I'm telling you, get the shitty Sovteks (that's what they came with) out of the thing! Mine would cut out now and then with bad tubes also. I doubt it's a cap- too new of a box. It's easy, then, after you swap out tubes, if you still want you can start testing for bad components if the problem hasn't cleared up *YUK* (I'd rather be making music for sure).

And I think those units were "burned in" already at the factory IIRC.

What's not working? With NUendO- that I can believe. Are you using the digital converter? Nuendo might not like the 18 bit converter on the digitech. I don't know.

Ummmmmm.. may be I'll try to change the tube first then I'll anoying you again :D Thanks man!
The Nuendo and other stuff in my studio are working fine except new VTP1 in my rack next to 1178 :( . In put Ch. 1 is the problem
the signal from my tube mic or line instrument did't get through the unit well sometimes it's have a stable signal sometimes it's just gone (No signal record on Nuendo) I didn't use Digital out put much only analoge out put. If you have service manual for this unit. Would you please post it where I can download or e-mail me. That will be a big help
Thank you very much Wooly

I own two of the VTP-1's. I think their converters and EQ's are very good. However, I was never able to get what I consider to be an acceptably clean or nice-sounding signal through the tube section, no matter what kind of tube I tried, and no matter how I adjusted the bias.

Eventually, I simply pulled out the tube section and replaced it with a simple 4560 opamp circuit with similar gain. Now, I use the things as utility boxes all the time, as preamps, converters, eqs, level shifters, etc.

Sooo.... if you are on a quest for that mythical tube pre mojo, toss them. Or sell them to me!

That was interesting idea Anxious! I'd like to re-cap all not working C & R. I'll change all of them to A grade stuff and swap tube latter. But I can't find service manual on the web. :? too bad
How about the 20 Db Pad circuit? Is it FET?

This was several years ago, but I remember getting a service manual from Harman. Might have cost $19, or something. Next time I unlock my storage unit, I'll see if I can find manual for you. I might even have the Circuitmaker files for the amps I built. No FET's that I recall.

KB wrote: That was interesting idea Anxious! I'd like to re-cap all not working C & R. I'll change all of them to A grade stuff and swap tube latter. But I can't find service manual on the web. :? too bad
How about the 20 Db Pad circuit? Is it FET?

That would be great anxious!
Thanks you guys for all info.