• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Excellent NOS Russian 6Pi3C/6N3C (6L6GC) Tubes...

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I just got in my matched quad of NOS Russian output tubes for my Baldwin amp yesterday. The main reason for buying these tubes was just to get an inexpensive quad of output tubes to diagnose a slight noise issue with my amp that was being put through the speakers. The noise wasn't loud, but it was quite annoying none the less. I wasn't sure if it might have been the output tubes (as I already swapped the preamp and rectifier tubes) and still had the noise. I was starting to wonder if it might have been the 50+ year old coupling and/or bypass caps. After replacing the Chinese Shuguang 6L6GC's with these Russian 6Pi3C's, the speakers are absolutely dead silent. No hum, hiss, crackle, sizzle, pop, tick... Nothing. So apparently it was the 6L6's causing the problem.

I put the 6Pi3C's in and had them running for approximately 2 hours last night before heading to bed, and I have had them running since 7am this morning. So far, these tubes sound great!

Mind you, I'm not ranting and raving over them, but these tubes sure do sound extremely good for the money. They still have the impact and massive bass control of the 6L6's driving my NHT 2.9's, and they still have that smooth, extended top end of the 6L6's, but what they add into the mix is the warm, full glowing sound in the midrange, much like a EL34/6BQ5 or SE amp. It's the best of both worlds.

Of course, YMMV considering the amp(s) you use these Russian tubes in, but I do urge you to try them out in your setup. I'm sure you won't be disappointed. And at their price point on eBay, you can't go wrong. I paid about 20 bucks more for mine than most of the listings on eBay only because I wanted them ASAP and the NOS ones I found were in California, not in Russia, Ukraine, etc, etc.

Please don't listen to the people who say these tubes are junk and don't sound good. My NHT's are quite detailed and respond very well to differences in the signal chain, both good and bad.

Here's a couple iPhone pics of them, one at night and one during the day. As you can see, they also have that blue glow to them...


I just went to AudiogoN and found one of Will Vincent's amps for sale (a modded Dynaco ST-70) and sent him an email regarding the technical specs of this Baldwin amp. I hope he replies back soon. I too would like to know what the different voltages are in this amp.

On another note, I'm still listening to this amp and boy do these new tubes sound good!

Speaking of tubes, I asked him a question which is probably a stupid one and am almost afraid to ask here, but I asked him if this amp is capable of running EL34 tubes. I have read that some amps can swap between 6L6's and EL34's all day long, but I think it might have something to do with the actual design and/or power supply transformer. I just figured I'd ask anyway.
How do you tell if your tubes have gas? And how do you tell if it's gone?

(My wife considers me an expert at evacuating gas, but I think there's always something new to learn.)

(Sorry for being off-topic.)


I had some 6P3S run away. That means, they had gas. :D

Clean tubes have higher negative potential on the grid than supplied from bias source, due to electron cloud. Gassy tubes have lower negative, or even positive voltage drop on a grid leak resistor.
Nice amp Chops!

Here is mine (6П3С-Е tubes):


Thanks Wave! Likewise with your amp! Nice and colorful. :D

BTW, under close inspection just a few minutes ago, I noticed that the blue haze not only nearly covers the entire sides of the tubes, but also pulsated with the music as well as intensify as the volume gets turned up. I'm assuming this is normal?...

I'll see if I can get some good pictures in complete darkness and post them up in a few.
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