Relay switch for Cascode in 800-2203 style build

[Blackhawkamplifiers]

I am designing a modified JCM 800 with 2203 power section. To maximize gain with three 12AX7 tubes I have added a cascode. I would like to use a relay to remove the cascode as a clean channel. I am aware of the volume jump this will cause and will compensate for it if necessary. I'm reading that the relay popping that happens in high gain amps is worse the earlier in the circuit it is. I might need to introduce the cascode AFTER the first two gain stages as I have included it at the beginning of the circuit.
If anyone has any layouts or instructions which include implementimg a relay to add/remove a gain stage, please advise. I have included a drop box link to a PDF of my board layout.

https://www.dropbox.com/s/c3skymbg1cp4nnq/nocturne.pdf?dl=0

[tubenit]

ARCHIVES has a bunch of information about installing Doug's relay switching which I highly recommend and use in my amps.

http://el34world.com/Forum/index.php?topic=14348.0

I am not sure how'd one add a cascode that is switchable (or if it's switchable)?   Cascade switchable is easy to do.  Did you mean cascode?

http://www.valvewizard.co.uk/cascode.html

With respect, Tubenit

[EL34]

My advice on figuring out switching is to draw the circuit out with both possible outcomes when the switch is in both positions
Relays are just switches that you can control remotely

So for example in the image below

The left half is one switch position and the right half is the other position
It's a DPDT switch, so two things can be switched independently and at the same time

In the left half the signal from V1A goes through the switch on to V2A And V1B's input grid is switched to ground to shut off the tube

In the right half, the signal from V1A goes to V1B and then to V2A
An extra gain stage is switched in by doing this

[Blackhawkamplifiers]

ARCHIVES has a bunch of information about installing Doug's relay switching which I highly recommend and use in my amps.

http://el34world.com/Forum/index.php?topic=14348.0

I am not sure how'd one add a cascode that is switchable (or if it's switchable)?   Cascade switchable is easy to do.  Did you mean cascode?

http://www.valvewizard.co.uk/cascode.html

With respect, Tubenit

Yes a cascode indeed :) one triode chained into another. Should be interesting to say the very least. I had searched a bit and not yet found what you recommended so thank you very much!

[tubenit]

I will offer my thoughts on the cascode switching.   Keep in mind that the cascode (per valve wizard) is to imitate a pentode.

I built an amp where V1 switched between a 5879 pentode and a 12A_7 triode.  Sort of Marshallish TBM topology.

I was thinking the 5879 would be my boosted/fat tone and the 12A_7 was my clean tone.   And indeed the 5879 was a fatter tone and the 12A_7 was a cleaner tone.

However,  it was NOT a useful significant difference for me & I quickly changed out that approach for something different.

I think you are likely to have popping problems switching a cascode (vs cascade) out?  I can't see how that wouldn't happen?

You may be better off using Hoffman's  " hot switch mod"  or using a 5879 as an OD boost.

With respect, Tubenit

[sluckey]

Show us the schematic that your board layout is based on.

[Blackhawkamplifiers]

Show us the schematic that your board layout is based on.

I have yet to draw one

[sluckey]

Show us the schematic that your board layout is based on.

I have yet to draw one

How do you draw a complicated layout without a schematic?

Here's a switchable cascoded gain stage...

[tubenit]

That's really an odd design, IMO.  Switchable cascode V1 cascaded into the next triode.  I would think that would be difficult to do without loud popping or such a dramatic volume increase that going from cascode to clean on the fly
that it  wouldn't be useable on the fly?


When I kept reading switchable "cascode",  I kept thinking making those triodes cascode  & then the same triodes uncascode.  I can sure think of other approaches that would make more sense o me going from OD to clean on the fly.


with respect, Tubenit

[Blackhawkamplifiers]

That's really an odd design, IMO.  Switchable cascode V1 cascaded into the next triode.  I would think that would be difficult to do without loud popping or such a dramatic volume increase that going from cascode to clean on the fly
that it  wouldn't be useable on the fly?


When I kept reading switchable "cascode",  I kept thinking making those triodes cascode  & then the same triodes uncascode.  I can sure think of other approaches that would make more sense o me going from OD to clean on the fly.


with respect, Tubenit

Well haha this is my first channel switching amp and I am relatively experienced wth single channel amps I am breaking new ground. I am always a fan of trying things that are original however there is a reason for traditional approaches in that they work haha. I'll give this a shot and if it's not effective then I'll try something else. Sometimes it's the most helpful to put ideas like this out there to have people tell me if my ideas are just plain crazy haha

[Blackhawkamplifiers]

Show us the schematic that your board layout is based on.

I have yet to draw one

How do you draw a complicated layout without a schematic?

Here's a switchable cascoded gain stage...

That's exactly how I had planned to run it! Awesome thank you!

Also, I tried to attach the original layout I drew mine from but my phone isn't letting me.