HRM/D-uator/Reverb all in one amp- new layout posted

[Bob-I]

EDIT:

I spent quite a bit of time on the layout, but it's not complete. I'm missing some obvious wires and the relay supply (I'll be using the 5V windings.

Some notable things.

1) Loop bypass switch, simply connects the in to the out.
2) Reverb bypass switch, simply connects the in direct to the PI input, therefore bypassing the balance resistor too.
3) Added mid boost to the relays.
4) Supply filters, expect for the main filters are all 450V. I'm only using a 300-0-300 PT so that'll be fine, even unloaded it'll be around 430V on power up.
5) It'll be a 4 -6V6 amp. I have 200ma of B+ and 6A heaters so I should be fine with 4 6V6's and 5 12AX7's. My OT is 4200ohms/40 watts, again my calculations say ok.

Thx everyone for your input.

[pamaz67]

Hi Bob.
Probably you're not crazy in your desire to fit all the "accessories" in the amp case. Think about fuchs amps ( i know the rev is solid state)
Anyway I can play reguraly a fuchs 30 that runs on 4 6v6 and have to say that the tone is wonderful, very full and harmonically rich.
On the other side it's missing that slamming energy that comes from 6l6 amps ( 50 or 100w).
As you are aware the fuchs can run on 2x6l6 too, but the plate voltage is not enough to get that energy ( that is power at the very end) i was mentioning before.
Probably one of the best studio amp I can imagine, but not enough ( for my taste) for live situations.

Ciao
Paolo

[Bob-I]

Hi Bob.
Probably you're not crazy in your desire to fit all the "accessories" in the amp case. Think about fuchs amps ( i know the rev is solid state)
Anyway I can play reguraly a fuchs 30 that runs on 4 6v6 and have to say that the tone is wonderful, very full and harmonically rich.
On the other side it's missing that slamming energy that comes from 6l6 amps ( 50 or 100w).
As you are aware the fuchs can run on 2x6l6 too, but the plate voltage is not enough to get that energy ( that is power at the very end) i was mentioning before.
Probably one of the best studio amp I can imagine, but not enough ( for my taste) for live situations.

Ciao
Paolo

Thx for the reply. Yes I agree that you lose the slamming energy, but that's never really been my sound. I like the creamy rich harmonics of the 6V6 amp, plus it's really plenty aggressive.

[jelle]

I did almost the same thing in a superreverb chassis (I thought I was crazy trying..turned out fine!)

Btw the peolpe who are NOT asking themselves " am I crazy to try this?" often are...

The loop is after the relay and the reverb is after the loop right before the pi in my amp. I love the 4x 6V6 config and I use JJ's at 450V. I am not missing any power whatsoever and if i want I can use the 100/50 switch.

Jelle

[Bob-I]

I did almost the same thing in a superreverb chassis (I thought I was crazy trying..turned out fine!)

Btw the peolpe who are NOT asking themselves " am I crazy to try this?" often are...

The loop is after the relay and the reverb is after the loop right before the pi in my amp. I love the 4x 6V6 config and I use JJ's at 450V. I am not missing any power whatsoever and if i want I can use the 100/50 switch.

Jelle

So your reverb is not in the loop?

[jelle]

reverb in the loop sounds like a very good idea but in my case I can use a chorus or something like it in the loop and also reverb from the amp itself.

Be carefull with the powersupply or your sound will change too much.....I ran mine parallel with the normal ODS string from the screen node but you might want to use a separate PS trannie etc. for it.

Jelle

[mlp-mx6]

I built one like you said except for the built-in reverb. Having played on too many "flexible" stages where the thunder crash was UNCOOL (when the band got dancing and wobbling the stage), I've gotten away from on-board spring reverb. Anyway - this amp was actually kinda like the TDS - one dedicated clean channel, and an ODS-style clean/OD, all switchable. I say go for it! (Isn't what you're proposing exactly what the Glaswerks SOD is?) In fact, with 6 preamp tubes you could have the TripleDrive approach PLUS the D'lator AND reverb, if you use the 1-tube reverb approach.

One preference I have is to have the reverb BEFORE the loop, so that the reverb wash is effected. For instance, if I have a chorus going, I like the reverb wash to be chorused - it's a really cool sound to my ears. This is different from reverbing the chorus. Just an idea/opinion...

Michael

[Bob-I]

reverb in the loop sounds like a very good idea but in my case I can use a chorus or something like it in the loop and also reverb from the amp itself.

Interesting idea. My goal was to turn off the reverb when using the loop. You've got me thinking.

Be carefull with the powersupply or your sound will change too much.....I ran mine parallel with the normal ODS string from the screen node but you might want to use a separate PS trannie etc. for it.

Jelle

I was thinking that I'll need about 6 stages of filtering after the main filters.

Screens || Reverb -> loop
PI -> OD -> CL

That's a lot of caps

[Bob-I]

I built one like you said except for the built-in reverb. Having played on too many "flexible" stages where the thunder crash was UNCOOL (when the band got dancing and wobbling the stage), I've gotten away from on-board spring reverb.

That's why I put a switch to disable the loop/reverb. Also I have the reverb disabled when you plug something into the loop.

I say go for it! (Isn't what you're proposing exactly what the Glaswerks SOD is?) In fact, with 6 preamp tubes you could have the TripleDrive approach PLUS the D'lator AND reverb, if you use the 1-tube reverb approach.

Actually if I go with the 4 6V6 idea it'll only be 5 preamp tubes. I'll need to use one for a power tube, plus the rectifier socket for the 4th.

One preference I have is to have the reverb BEFORE the loop, so that the reverb wash is effected. For instance, if I have a chorus going, I like the reverb wash to be chorused - it's a really cool sound to my ears. This is different from reverbing the chorus. Just an idea/opinion...

Michael

Hmmm......

[heisthl]

http://ampgarage.com/forum/download/file.php?id=1479 has all in one and I just used the PI node to run the 2 tube reverb with no issues after adjusting the dropping string values. I do believe in branching the PS for the loop. I am a firm believer in having reverb after the loop but one more relay (or DPDT switch) would give you the option of loop>reverb or reverb>loop as long as you don't put the reverb in the loop. As far as the crashing sound of a jarred reverb tank - the reverb footswitch kills the tank output.
Looks like a fun project you're starting....

[Bob-I]

...has all in one and I just used the PI node to run the 2 tube reverb with no issues after adjusting the dropping string values. I do believe in branching the PS for the loop. I am a firm believer in having reverb after the loop but one more relay (or DPDT switch) would give you the option of loop>reverb or reverb>loop as long as you don't put the reverb in the loop. As far as the crashing sound of a jarred reverb tank - the reverb footswitch kills the tank output.
Looks like a fun project you're starting....

Thanks for that.

I'll move my reverb to after the loop, and include a loop bypass too. I don't understand why you have 2 nodes for the loop though. You'd think one would be enough. At first I was thinking that the second node was for the reverb return, then I looked more closely. I'm using a one tube reverb so I should be fine on one node like you ran.

[FUCHSAUDIO]

I don't understand why you have 2 nodes for the loop though. You'd think one would be enough. At first I was thinking that the second node was for the reverb return, then I looked more closely. I'm using a one tube reverb so I should be fine on one node like you ran.

Bob: Technically, one node for a loop is usually cool. Having two does allow you to adjust the respective tube sections for optimal voltages. Whether it has a drastic impact on tone is subjective. Since all these preamp stages are class-a no current swing (to speak of) takes place, but the isolation (particularly in high gain amps), clean up low end and reduces the chance of oscillation. Just sayin'....

[glasman]

I think you may want to check the CF wiring in the schematic, it is not going to work correctly as shown in the schematic. There is no return path to ground for the grid.

EDIT :

The layout of the CF on the board pic is ok.


Gary

[heisthl]

The 2 nodes for the loop are so you can reduce the source voltage for the return stage.
On the schematic you have the output tubes getting plate voltage in standby. (not good)

[Mr. dB]

I think you may want to check the CF wiring in the schematic, it is not going to work correctly as shown in the schematic. There is no return path to ground for the grid.

EDIT :

The layout of the CF on the board pic is ok.


Gary

The schematic also lacks an output cap on the CF, present in the layout.