ODS 124 - revisited for the 21C

[Bombacaototal]

... Here is the Pentode amp ...

Off topic here, therefore only briefly to avoid misunderstandings: As far as I still remember the Pentode amp correctly after now around 25 years, the schematic talbany posted here isn't a correct representation of its circuit. E. G.: AFAIR V2 in the real amp is wired completely different than V2 in the schematic talbany posted here. So the designation of this schematic as “Inspired by Dumbleland Silver Alligator” seems to be chosen appropriately.

All the best,

Max

Max, I posted the correct schematic of the Alligator here. This is definitely my next amp, when things are less crazy busy
https://ampgarage.com/forum/viewtopic.p ... rt=150#top

[Max]

The Pentode Amp schematic talbany posted isn't correct.

All the best,

Max

[ChopSauce]

Mostly just wondering if building a silver alligator is worth the extra effort: what's the point in using pentodes only in triode mode?

[Max]

... what's the point in using pentodes only in triode mode? ...

That's just one of the errors in the schematic talbany posted. AFAIR this is different in the real amp.

All the best,

Max

[talbany]

... Here is the Pentode amp ...

Off topic here, therefore only briefly to avoid misunderstandings: As far as I still remember the Pentode amp correctly after now around 25 years, the schematic talbany posted here isn't a correct representation of its circuit. E. G.: AFAIR V2 in the real amp is wired completely different than V2 in the schematic talbany posted here. So the designation of this schematic as “Inspired by Dumbleland Silver Alligator” seems to be chosen appropriately.

All the best,

Max

Max, I posted the correct schematic of the Alligator here. This is definitely my next amp, when things are less crazy busy
https://ampgarage.com/forum/viewtopic.p ... rt=150#top

Thanks for posting this I had not seen this thread before?. I do remember working on doing this Pentode High voltage amp with you a while ago but did not know you completed a schematic..At some point I do want to build this amp..Will update my database

Tony

[Max]

Max, I posted the correct schematic of the Alligator here. https://ampgarage.com/forum/viewtopic.p ... rt=150#top

AFAIR this schematic isn’t correct either. E.g.: AFAIR V2 is actually wired as a pentode, but (at least AFAIR) not in the way shown in your schematic. So in the real amp (at least AFAIR) V2 and V3 are also wired differently than shown in your schematic.

All the best,

Max

[talbany]

BTW.Max do you still own the Silver Alligator amp?
Tony

[Bombacaototal]

Max, I posted the correct schematic of the Alligator here. https://ampgarage.com/forum/viewtopic.p ... rt=150#top

AFAIR this schematic isn’t correct either. E.g.: AFAIR V2 is actually wired as a pentode, but (at least AFAIR) not in the way shown in your schematic. So in the real amp (at least AFAIR) V2 and V3 are also wired differently than shown in your schematic.

All the best,

Max

V2 is a pentode on my schematic. But happy to get corrections if you know where the mistakes are...

[Stephen1966]

If I might butt in here, could I ask, why is the inductive field of the reverb transformer arranged diagonally on many of the chassis I've seen? I'm working on a plan for my chassis and I don't know what to consider in the placement of the reverb transformer.

Good health!

Stephen

[Max]

V2 is a pentode on my schematic.

I noticed and therefor I wrote that this is correct, but the kind of wiring it shown in your schematic AFAIR isn't.

... But happy to get corrections if you know where the mistakes are...

Please understand - even if it might be difficult - that after talbanys impertinent and also publicly on the internet asked question:

... Max do you still own the Silver Alligator amp? ...

about my private circumstances, my motivation to find ways of anecdotal descriptions for providing here the kind of information you requested (what btw I completely understand of course) – has just reached zero.

And please understand that I feel bound by my promises of confidentiality to the collectors and musicians who have kindly allowed me over the past 40 years to use their Dumble-made private property for my private enjoyment.

All the best,

Max

[talbany]

And please understand that I feel bound by my promises of confidentiality to the collectors and musicians who have kindly allowed me over the past 40 years to use their Dumble-made private property for my private enjoyment.

Good because we wouldn't want you to give away any design specifications on any one amp you might know about or have been in due to a "confidentiality" agreement with your collectors/ musicians or for financial gains, by criticizing the accuracy then refusing to clarify circuits we are attempting to reverse engineer here at the Amp Garage..That would be a real shame!

Tony

[rootz]

Calm down guys, please. Stephen is putting together a some designs of an amp (not the silver alligator by the way) and not in any way helped by an argument. I’m not going to pick a side, not will I comment any further on any matter, except for the ones related to the topic.

What was you question again Stephen? Diagonal placement is only there to prevent coupling between transformers: get the cores out of the same plane (not the one with the wings).

Edit: Stephen, you probably should have your own thread for your design.

[martin manning]

If I might butt in here, could I ask, why is the inductive field of the reverb transformer arranged diagonally on many of the chassis I've seen? I'm working on a plan for my chassis and I don't know what to consider in the placement of the reverb transformer.

Generally speaking it should be well away from the power transformer, with the coil axes oriented at 90 degrees. On Fender AB763 chassis, where the reverb driver transformer is mounted diagonally, it could be that that was done simply to get it to fit between the cap box and the edge of the chassis.

Edit: Stephen, you probably should have your own thread for your design.

I think that is what this thread was supposed to be, but it is pretty far off its rails now.

[rootz]

So far of rails sometimes I even forgot that Martin...

Good point about the placement, very limited space indeed.

[Stephen1966]

Calm down guys, please. Stephen is putting together a some designs of an amp (not the silver alligator by the way) and not in any way helped by an argument. I’m not going to pick a side, not will I comment any further on any matter, except for the ones related to the topic.

What was you question again Stephen? Diagonal placement is only there to prevent coupling between transformers: get the cores out of the same plane (not the one with the wings).

Edit: Stephen, you probably should have your own thread for your design.

Thank you rootz, and thank you Martin, you bring some much needed clarity to my project. I had to smile with your "edit". Should I be offended? Well, rest assured, I'm not. Is it possible that I could have been offended? I guess... but, I have learned not to make assumptions about what people think based on a turn of phrase or comment in passing. I, also, don't want to talk about this further.

Moving on, I am grateful for how you have developed this topic of different amplifiers, different circuits and so on. Perhaps it has been a little off-topic. But I don't see this as any cause for concern. Perhaps you don't realise it, but I read all your ideas and I'm learning all the time. So please, don't feel you have to be so focused on a single topic. I'm happy with the reverb circuit rootz designed but at his heeding, and from the discussion you have been developing, I'm also thinking about the 002 circuit and how that might implemented in my limited real estate of a chassis. It's simply fascinating to hear how you guys develop a subject and in there, I realise there is a methodology, several methodologies. Which, may (or may not) be immediately applicable for me at present, but... none of it is a waste of time. Suffice to say, I am really grateful for your contribution, the amp I'm building has already benefited greatly from the creative possibilities you have imagined if not already built in some other form, and, I hope you will continue your conversation here in the same spirit.

Thank you everyone.