A new 102

[Colossal]

Hi Guy,

No, the plate resistors I used are IRC GS-0 1% metal glaze and they have now gone extinct. There is very little stock left. I used all my 100k and now they are flat gone

Dave

[Guy77]

Thanks for the update Dave! Yes 100K is the values I look for the most too.

Oh well!

Cheers
Guy

[Aaron]

I think not all Rock/Jazz were done the same by the master. Here at 5:05 you can hear the massive gain drop on the jazz setting

https://youtu.be/sKunm4Z1IXA

J/R and Deep are all the same on every amp (Electrically)

Did you measure all your cap,pot and resistor values before you installed them?

If I get a chance I'll do a demo showing how they should work.


Tony

Hi Tony, I think the only difference is that some amps HAD the relay with the extra 22M and some were just the switch straight, but I agree that the circuit is always the same.

I’d love to see a demo showing how it should be, as I’ve seen real HAD amps (like the one from the video I linked) whereby there was a massive gain drop but have also seen others where it is not that evident like the Dumbleland below
https://youtu.be/zthE05CGFvY

Depends where the Deep switch is wired. In some amps the Deep switch only works in the Rock setting. If the Deep switch is wired for the Jazz setting as well, I’ve found with it on there isn’t much of a volume drop between Rock and Jazz, (or Mic).

[Charlie Wilson]

Interesting! I indeed found some Dumble photos that show the 270k coming off the deep switch going to the middle terminal of the jazz/rock switch. However, when the deep switch is not engaged, the deep switch end of that resistor does not contact anything. So I'm not sure how that would make a difference as far as volume drop.
CW

[Bombacaototal]

J/R and Deep are all the same on every amp (Electrically)

Did you measure all your cap,pot and resistor values before you installed them?

If I get a chance I'll do a demo showing how they should work.


Tony

Hi Tony, I think the only difference is that some amps HAD the relay with the extra 22M and some were just the switch straight, but I agree that the circuit is always the same.

I’d love to see a demo showing how it should be, as I’ve seen real HAD amps (like the one from the video I linked) whereby there was a massive gain drop but have also seen others where it is not that evident like the Dumbleland below
https://youtu.be/zthE05CGFvY

Depends where the Deep switch is wired. In some amps the Deep switch only works in the Rock setting. If the Deep switch is wired for the Jazz setting as well, I’ve found with it on there isn’t much of a volume drop between Rock and Jazz, (or Mic).

I was watching this video and at 3:50 Rock and Jazz have no gain drop at all
https://youtu.be/SNSAj6AzWGo

Interesting observation Aaron, I have my amps wired with Deep at Rock only. I shall try in the middle terminal of the J/R toggle to work at jazz as well as you suggested

[Aaron]

Interesting! I indeed found some Dumble photos that show the 270k coming off the deep switch going to the middle terminal of the jazz/rock switch. However, when the deep switch is not engaged, the deep switch end of that resistor does not contact anything. So I'm not sure how that would make a difference as far as volume drop.
CW

Hi Charlie,
When the 270k is wired to the middle lug the Deep switch can be used in Jazz setting. I found it doesn't make the volume drop as noticeable with the Deep switch on.
I didn't take notice of the wiring until I built the Pentode Amp.
Thanks,
Aaron

[Aaron]

Hi Tony, I think the only difference is that some amps HAD the relay with the extra 22M and some were just the switch straight, but I agree that the circuit is always the same.

I’d love to see a demo showing how it should be, as I’ve seen real HAD amps (like the one from the video I linked) whereby there was a massive gain drop but have also seen others where it is not that evident like the Dumbleland below
https://youtu.be/zthE05CGFvY

Depends where the Deep switch is wired. In some amps the Deep switch only works in the Rock setting. If the Deep switch is wired for the Jazz setting as well, I’ve found with it on there isn’t much of a volume drop between Rock and Jazz, (or Mic).

I was watching this video and at 3:50 Rock and Jazz have no gain drop at all
https://youtu.be/SNSAj6AzWGo

Interesting observation Aaron, I have my amps wired with Deep at Rock only. I shall try in the middle terminal of the J/R toggle to work at jazz as well as you suggested

Hi Raf,

Notice the Deep switch is on when he switches between them.

Also, don't forget that amp in the video isn't a real Dumble

Thanks,
Aaron

[Bombacaototal]

Aaron, thanks for the note regarding the Deep. Ha, he got me fooled there, I really thought it was a real one

[norburybrook]

[

Depends where the Deep switch is wired. In some amps the Deep switch only works in the Rock setting. If the Deep switch is wired for the Jazz setting as well, I’ve found with it on there isn’t much of a volume drop between Rock and Jazz, (or Mic).

I think that's what I was eluding to i my earlier post.

M

[Charlie Wilson]

Depends where the Deep switch is wired. In some amps the Deep switch only works in the Rock setting. If the Deep switch is wired for the Jazz setting as well, I’ve found with it on there isn’t much of a volume drop between Rock and Jazz, (or Mic).

I was watching this video and at 3:50 Rock and Jazz have no gain drop at all
https://youtu.be/SNSAj6AzWGo

Interesting observation Aaron, I have my amps wired with Deep at Rock only. I shall try in the middle terminal of the J/R toggle to work at jazz as well as you suggested

Hi Raf,

Notice the Deep switch is on when he switches between them.

Also, don't forget that amp in the video isn't a real Dumble

Thanks,
Aaron

I don't want to totally derail the thread but I remember awhile back someone said that green amp was not a real Dumble but that was never elaborated on. I think Doug Doppler thinks it is an original and if it was on loan from Henry Keiser, I find it hard to believe that a friend of Dumble would own a clone. Just my 2 cents.
CW

[talbany]

AFAIK That amp belongs to Henry Keiser who has quite a few Dumbles and is good friends with HAD
https://www.youtube.com/watch?v=VuTLl1JbUdM

The Green amp in the Doppler vid and the Blue one in the vid above. He also owns an SSS I believe is a Blackface. I have a friend at Two Rock who has been in both amps. Interesting Charlie that Dumble wired the connection on the R/J switch differently. could this have something to do with the center off PAB function there? . Most of the ones I've seen have it coming off the bottom contacts of the R/J switch. If you want it to work on both settings you need to attach it to common (middle contacts) on the DPDT. I'll go back over some shots again and see if I can find an amp wired this way. could be and I just missed it. Not that I don't doubt you CW. If I find one will post it..Either way, you can obviously wire it however you want.
That clears that up hopefully.


BTW. Bill at Sebago amps who is good friends with Goofeydog (host in the video) told him it was on load from Keiser as a 2nd source.
Tony

[norburybrook]

interesting. I always thought it was the real thing but it was Jelle Welagen who first told me it was a fake. I don't know how he knew and he never elaborated.



M

[Aaron]

AFAIK That amp belongs to Henry Keiser who has quite a few Dumbles and is good friends with HAD
https://www.youtube.com/watch?v=VuTLl1JbUdM

The Green amp in the Doppler vid and the Blue one in the vid above. He also owns an SSS I believe is a Blackface. I have a friend at Two Rock who has been in both amps. Interesting Charlie that Dumble wired the connection on the R/J switch differently. could this have something to do with the center off PAB function there? . Most of the ones I've seen have it coming off the bottom contacts of the R/J switch. If you want it to work on both settings you need to attach it to common (middle contacts) on the DPDT. I'll go back over some shots again and see if I can find an amp wired this way. could be and I just missed it. Not that I don't doubt you CW. If I find one will post it..Either way, you can obviously wire it however you want.
That clears that up hopefully.

BTW. Bill at Sebago amps who is good friends with Goofeydog (host in the video) told him it was on load from Keiser as a 2nd source.
Tony

Hi Tony,
I’ll have to go through some pics to find the amps that have the Deep wired to the middle lug. But the Pentode Amp is one.
Thanks,
Aaron

[talbany]

AFAIK That amp belongs to Henry Keiser who has quite a few Dumbles and is good friends with HAD
https://www.youtube.com/watch?v=VuTLl1JbUdM

The Green amp in the Doppler vid and the Blue one in the vid above. He also owns an SSS I believe is a Blackface. I have a friend at Two Rock who has been in both amps. Interesting Charlie that Dumble wired the connection on the R/J switch differently. could this have something to do with the center off PAB function there? . Most of the ones I've seen have it coming off the bottom contacts of the R/J switch. If you want it to work on both settings you need to attach it to common (middle contacts) on the DPDT. I'll go back over some shots again and see if I can find an amp wired this way. could be and I just missed it. Not that I don't doubt you CW. If I find one will post it..Either way, you can obviously wire it however you want.
That clears that up hopefully.

BTW. Bill at Sebago amps who is good friends with Goofeydog (host in the video) told him it was on load from Keiser as a 2nd source.
Tony

Hi Tony,
I’ll have to go through some pics to find the amps that have the Deep wired to the middle lug. But the Pentode Amp is one.
Thanks,
Aaron

That would be great Aaron.Again not that I doubt anyone. Just looking for the proof

[talbany]

interesting. I always thought it was the real thing but it was Jelle Welagen who first told me it was a fake. I don't know how he knew and he never elaborated.



M

A quick search of the word Doppler. BTW.. That amp is a 4th generation "Classic" (like the one I just finished). I wonder what power tubes were in that amp at the time of the video?

https://ampgarage.com/forum/viewtopic.p ... er#p121730

Tony