The guys here can help you get it running.  I would ask if you have tried it out yet but it seems like you know it has a problem..what did the seller say about it was it listed for parts or something? 

I would say plug it in and try it but I would hate to see it burn up some impossible to find outputs or something.

T4 E to B  0.3V

T1 E 0.6v
   B 0v
   C -35.8v

T2 E 0.6V
   B 15.1v
   C -36.5v

R5 671 ohms

D1 checks good

So looks like T1 is bad?

Is there anyone in the south west of the UK who would like to look the amp over? It may not have much wrong with it at all. Small funds are available.

Quote from: Bandito on April 06, 2024, 04:15:56 PMWould this one work? https://www.hotroxuk.com/accutronics-blue-reverb-amc2bf3.html

That is too low input impedance.  If you want to go with that miniature type, use the AMC2EF2.  In my experience, the miniature type do not sound very good.
If there is not enough room for a 17" tank you can get a 9" type.  For MOD or Accutronics brand, 4EB2C1B is 17", 8EB2C1B or 9EB2c1B are 9" long types.
You may find them for less money at other UK sellers, like Watford valves, etc.

Quote from: g1 on April 05, 2024, 02:03:37 PMShows 600 ohm impedance for the tank so 4EB2C1B tank should work.

Would this one work? https://www.hotroxuk.com/accutronics-blue-reverb-amc2bf3.html

Thanks for your comments! Do you reckon this to be a good amp, worthy of resurrection?

Sometimes the removal and re-install of tubes will clean up (deoxidize) the sockets.  Maybe that got it working.

Depending on the droning sound, it could be a microphonic tube.  Try tapping them gently one at a time, or holding them with a rag or something to damp the vibration but keep from getting burned.  Generally, microphonic preamp tubes will be higher pitched whistling or squealing, where power tubes will more likely rattle or make low pitched rumbling sounds.

The E to B voltage of T4 (0.3V) seems to not be enough to turn it on.  Maybe checking directly with probes at E and B will give a more accurate reading than checking voltage to ground.
The voltage to turn it on should be developed across R5.  That is created because of current through T1.  What are E,B,C voltages for T1 and T2 ?

Well guys I promised I would give you a 💔 break but I have one more post to further confuse everything.  I put everything back together and the amp played very well normal then bright channel rockin like crazy and at 1/4 volume very loud


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About the only thing I can add is that (it seems maybe I'm wrong) that I lost some gain/overdrive after a few minutes like I had turned my tone knob down on my guitar.

And there is a hollow present hum/drone kinda like a distant vacuum cleaner.

But wow the bright channel was really nice and crispy just banging out the intro to lonely is the night then you shook me all night

Anyhow guys have a great weekend

Be safe

 

Ok I'm going to report some more info the give you guys a break 

Turns out there are three JJ EC83S and one Russian 12ax7

Markings are...

7025/12AX7WA
Made in Russia
0610

Anyhow I put some gloves on and preserved and was able to pull and remove swap tubes

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They all light up..and as was mentioned by a helper earlier turns out the Soviet tube doesn't illuminate much with the cover back on

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So I was kinda hoping that it would be easy enough and just buy a tube but idk at this point.

Also all of the tubes are lighting up good so idk...

Anyhow I enjoyed that anyway it was fun I still learned a bit.

Thanks