Spetel Logo


The Novik, Spetel, Petersburg, Red Bear Connection



I have owned a russian made, "Spetel" branded tube amp for the past 10 years or so that was sold to me as being a prototype of a Petersburg amp.
If memory serves me correctly I paid 500 swiss franks for it at the time, somewhere between 1993 and 1995. It's a basic 1 channel, 2 input, gain and master volume type amp that puts out around 100W and sounds quite nice.
I never cared much about it's origin writing it off as a marshall knock-off but I recently decided that it was about time to retube it since the old tubes had been in there for a long time (I haven't been using the amp for a few years so they haven't actually seen that much use). I tried finding info on the web but this did not turn up a great lot of info. Even trying to find some info for Petersburg or Red Bear amps is not an easy task (and those were my only leads).
What I have gathered is that this amp was probably made by Novik (they may not have called themselves Novik at the time). Apparently in the beginning they sold some amps branded as Spetel which according to a thread I found in a swedish forum could stand for Sankt PEterburg TubE Laboratory (the thread has expired so no link unfortunately). These amps probably were marketed later on as Petersburg and through collaboration with Gibson as Red Bear (I do not know if there is any connection to Sovtek amps). I remember a review of the Petersburg P100 in the german "Gitarre & Bass" magazine in the mid or late nineties and the chassis layout and some other details were absolutely identical to my Spetel. There's a guy in Germany who supposedly worked on the development of the Petersburg amps: here's their website. I definitely need to write him and ask for his view on this amp.
Update: Ralf Reichen from tonehunter.de told me the following. Petersburg and Novik amps were designed and brandnames by Ralf Reichen. A man called Sergei Poljakov was contracted to build (some/all?) Petersburg amps and apparently he also built the Spetel amps but it is unknown who contracted him to build them. Unfortunately Mr. Poljakov passed away about 10 years ago and I could not find any reference to him anywhere. But there you go, german engineering manufactured in Russia, can't be bad.

I had this amp retubed a year or 2 after I bought it and the tech (not really a tech in hindsight) just put EL-34 in there for power tubes and 12ax7 as pre-amp tubes without any modifications. The original tubes had russian designations and not being the tech-head that I am now I trusted the tech's judgement. After looking at all the info I had and tracing the circuit of my amp it became obvious that it was not wired for 12ax7 but for the russian 6H2Π  (6N2P) tube, it has the same pinout as the 12ax7 but with the difference of a 6V filament instead of a 12V like the 12ax7. The original power tubes were also russian (isn't that weird ;-), designated 6Π3C-E (6P3S-E) which seems to be a russian version of the 5881/6L6WGC, although I hear it's really a tube of it's own with similar specs. Datasheets for these tubes can be found at www.tubes.ru. I luckily had never thrown away the original power tubes or I would have put EL-34 in there again.

Update: I have received my tube order and installed them. I installed Sovtek 5581/6L6WGC in the poweramp section and 6H2Π-EB in the preamp section. First impression is very good but they will be put to the test next week during practice. Seems the preamp has a bit more gain than with the 12AX7 I had in there before.
For the technical-minded among you. Plate voltage on this amp is 488V. The amp has a bias trimmer installed internally and interestingly the maximum idle plate dissipation I could set it to was about 16.5 Watts per tube. Seems there is no way to bias the tubes too hot without mods. The bias range I get from the trimmer is very small (it's only a 10k trimmer). I suppose this would be easy to change but I left it for now.

I searched high and low for schematics of this amp but was not succesful. Same goes for Petersburg amps. There's an unofficial Red Bear page which has some info and a link to Triode Electronics where you can find schematics for Red Bear amps but unfortunately the quality is such that I couldn't make out most of the component values (probably blame Gibson for providing such lousy scans).
So I traced out the circuit of my amp (I encourage you to compare it to say a Marshall 2204 and count the differences). I'm providing this schematic for educational purposes only and I cannnot guarantee it is 100% accurate! This goes for all of the information on this page. Should you find obvious mistakes I welcome your input/feedback/questions. You can write me in english, german, dutch or french(keep it simple).
Also, if there's anyone out there who owns one of these, I would definitely love to hear from you!

I put this page up in the hope that someone might find this stuff helpful or interesting.
A final word, DISCLAIMER: This is not meant as an encouragement to open up your amp and start poking around. Tube amplifiers contain lethal voltages and as such can terminate your life without a fuss. DON'T do it unless you know what you're doing!.

Now here are some pictures of the amp, enjoy (Click on the thumbnails for a larger view):

Unfortunately at some time the logo plate broke in half (this was my regular gigging amp back then) and was lost over the years. It was a black rectangular plastic plate with white lettering and a fine white border. Look at the image at the top to get the general idea.



Bastian Michl (b_michl@REMOVETHISgmx.net) was kind enough to send me some pictures of his Petersburg P-100. The image with the red circles provides some clues as to russian manufacturing practices: use whatever parts you have lying around(nuts). Also, if anyone can make out what the hand-written words are supposed to read let us know! Bastian slightly modded his amp installing a hum balance pot on the heater winding. The filter caps were replaced too, as well as the power indicator led that had burned out.



Mark Reimer kindly sent me a couple of shots of his Red Bear and granted me permission to post them here. Since the original tolex was missing he redid it with some beautifull looking red vinyl. Excellent job!



Last changed 2008.7.2