The Amp Garage

I have a 67 Princeton Reverb. I am getting a buzzing from the cabinet on low notes. It doesn't happen when I use an external cabinet. I changed the speaker and tested it before I mounted on the baffle and it didn't buzz. I mounted it on the baffle and the buzz came back. The screws holding the baffl...

It did have octal tubes originally.

Thank you for your replies.

I bought this amp back in the late 80's. I think It was a 5c3. The previous owner had the octal preamp tubes changed to novals. There is also a mod that looks like a bias adjustment. Is this there to adjust resistor value? Can anyone tell me what this mod is and why they would do it. This speaker is...

Great suggestion.
It cured my problem.
Thank you.

Is there continuity between ground and cathode for v1 pin 3? Voltage for pin1:340v is indicating no current flowing. Normally you would see a high voltage at pin3 when there's no ground. Socket would be my first suspect. I have continuity from pin 3 to the resistor/capacitor. I have continuity from ...

I built a 102 with a precision power supply. Everything was working fine. I took the inputs apart in order to add a switched pot to the fet. The clean channel works with and without the fet switched in. I pulled the od relay out of the socket and manually jumpered it to test it. The od relay is work...

I bought 3 matched quads of these probably 25 years ago. They are Russian coin based 6l6/5881 tubes. I started to insert them into an ODS 102 build using Belton sockets. The tubes fit very loosely in the sockets. They wobble a lot and I wouldn't trust them to keep contact. I tried some 6l6 pulls fro...

I put in a 12at7 and the voltages came up a little.
I tried a different pan and it still didn't work.
I played it a while and the reverb came on.
I put the old pan back in and it still works.
It must have been a bad connection.

I'll keep an eye on it for a while.

Thanks for the suggestions.

I will try a 12at7 and see what happens.

AN Wonderland/JM 100 reverb problem I have built the amp using Taylors' boards and chassis. I used the layout in the JM/wonderland thread. https://ampgarage.com/forum/viewtopic.php?f=4&t=29774&hilit=jm+wonderland Everything works except for the reverb. I get no reaction to turning the send and recei...

It's good to know that the cap doesn't matter.
I don't have a schematic but the gut shot in the 7th photo shows the mod.

Thanks

I have a 53 Deluxe with a replacement OT and modded to use 9 pin preamp tubes.
It has a three prong plug but it looks like they left the death cap in.
Why?
It also looks like there is a bias adjustment.
Again why?

http://imgbox.com/g/4yE8Rw79qD

I checked the 5c1 layout against the amp.
They are the same.
The 5c1 schematic matches also.
My PT is a Triad 6500.
The only numbers on my ot are either TS537 or TS587.
It sounds really weak.
All of the caps are original so I'll start there.

No.
I think that is for the reissue. I have the 1953 version of the 5B1.
I looked a the layout and schematic for the 5c1 and I think they are the same as my 5b1.
Thank you.