Welcome to Solid State Guitar Amp Forum | DIY Guitar Amplifiers. Please login or sign up.

May 02, 2024, 11:04:41 PM

Login with username, password and session length

Recent Posts

 

Recent posts

#71
The Newcomer's Forum / Re: saturated's all encompassi...
Last post by saturated - April 09, 2024, 07:25:35 PM
Meanwhile....onward through the fog.  I am still holding out hope that I can get a trace on this Heathkit oscilloscope.  I ordered the four ICs for it and now I thought I would investigate this power supply by removing caps and reinstalling if testing good.

You cannot view this attachment.

Unfortunately (or fortunately) I have removed two and both tested (presumably) good

You cannot view this attachment.


So back in they go

Except...hmmm no way here to test leakage so I checked DC ohms with my meter and I have one that charged up pretty quick to about 70 kohm but then really slowed down

So idk maybe it's leaky

You cannot view this attachment.

But as I type it's still creeping up in fact it's at 130 kohm now so maybe it's ok.

 :(






#72
Amplifier Discussion / Re: Diagnosing a Fender bass a...
Last post by Den. - April 09, 2024, 06:27:37 PM
Quote from: g1 on April 08, 2024, 08:04:14 PMI think there may be some confusion now about the 'distorted sound'.
You are getting the proper sound of the Boss pedal using the FX return?

Yes, I am getting the proper DS-1 distorted sound as expected from that pedal.
Also, I neglected to mention that I had also tried a patch cord between the Send and Return jacks with no improvement.
#73
Tubes and Hybrids / Re: Tube Amp Trouble
Last post by saturated - April 09, 2024, 05:20:43 AM
Thank you sir I am glad I did not have to touch any power tubes...in the back of my mind I had heard about tube biasing and was dreading having to do something like that.  But I looked it up and evidently preamp tubes are just plug and play...?

The two 12ax7 I switched positions were in there really tight.  To avoid broken glass and blood I put on a leather work glove.

I really appreciate everyone's help with this idk what we did but it's sounding really crazy nice it still has a little hum at low volume but I ain't touching it right now.

8)
#74
Amplifier Discussion / Re: Marshall VS100R transistor...
Last post by g1 - April 08, 2024, 08:08:34 PM
Yes it would seem T1 is bad as you verified R5 and D1.  But you also need to check their solder connections.
As T1 and T2 form a differential amplifier, it is best to replace them as a pair.
#75
Amplifier Discussion / Re: Diagnosing a Fender bass a...
Last post by g1 - April 08, 2024, 08:04:14 PM
I think there may be some confusion now about the 'distorted sound'.
You are getting the proper sound of the Boss pedal using the FX return?
#76
Amplifier Discussion / Re: Diagnosing a Fender bass a...
Last post by Jazz P Bass - April 08, 2024, 07:38:47 PM
It appears to be a power amp issue.
#77
Tubes and Hybrids / Re: Tube Amp Trouble
Last post by Tassieviking - April 08, 2024, 11:37:25 AM
Just remember that big power tubes can get VERY heavy, just pull one out when it's hot and try to hold it in one hand, I bet you can't hold it for too long.
But everyone has to learn that certain things are hot the hard way, I am constantly reminding myself that the soldering iron is too heavy to hold on the pointy end. (The hard way)
#78
The Newcomer's Forum / Re: Londoner L100, Sound City ...
Last post by saturated - April 07, 2024, 09:49:47 PM
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.

#79
Amplifier Discussion / Re: Marshall VS100R transistor...
Last post by markorock37 - April 07, 2024, 08:57:53 PM
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?
#80
The Newcomer's Forum / Re: Londoner L100, Sound City ...
Last post by Bandito - April 07, 2024, 09:35:07 AM
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.