Triple Header Amp Build???

[Paul1453]

I thought it would be best to separate this from the junk gear thread now.

Musicians are creative, but I'm not a great musician so how about using some of that creativeness in building a unique creative amp?  I'm also not an electronics engineer, so in building an amp I need to follow some tried and true designs.  But building clones of these amps leaves that creativeness out of the equation.  I want to try to employ my creative side in building a unique triple head design into my recent junk gear purchase.  You can check the junk gear thread for some of my ideas on this proposed build up to this point.  I would appreciate any help any of you would be willing to offer in making my idea into a reality!  Will I be able to make this silly dream into a reality?  Maybe, with a little help from my friends!

I got this great rack mount case with a PT and choke very cheap, and I'd like to use this as the foundation to build my dream triple head amp into.  Attached is a picture of where this is at right now.  The PS really shouldn't use any 0D3 tubes in it, but I WANT it to have that nice purple glow coming out the front of the rack.  My friends and family really couldn't care less about what tubes are inside and how they sound, but maybe they will relate to that nice soothing purple glow coming out the front that fluctuates with the music???  So I have half assedly mounted an octal socket and 0D3 tube in the too big hole in front of the window where a large cap can used to be.  I put two octal sockets on the signal side of my case, where two other cap cans used to be, and I can barely manage to squeeze two metal 6L6 tubes in there, but they do fit.  Three 12AX7s are lined up leading to two 6BQ5s using all five of the sockets from this gear's former life.  I've mounted my only PP OT in what seems a reasonable spot for now, and I've marked with a sharpie two possible locations to add 7 pin sockets for 6AQ5 tubes.  I'm just putting parts together in potential spots to see how they fit for now.

The plan is to start with building a tried and true PP 6BQ5 design.  Always keeping in mind the ultimate goal of adding two more amp circuits to this later.  I want to reuse the preamp section of this first amp in the designs of the 6AQ5 and 6L6 amps to be added later.  The goal is to have amp sections that come together through a rotary switch on the front of the amp.  Position 1 a nice chimey sounding 6BQ5 amp, Position 2 a warm and slightly dirty sounding 6AQ5 amp, Position 3 a more Metal dirty sounding 6L6 amp.  All with that funny purple glow pulsating out the front of the amp.

I would sincerely appreciate any ideas, critiques, or suggestions you guys have along the way.  I'm also willing to freely share the completed design schematics with you all if anyone wanted to copy this work and build one of their own.  That is if I can manage to make this dream into a reality with all your help.   

[tubenit]

I've read your post 3 times and simply don't understand what you are doing or what you are saying? 

Can you please post a schematic?   

With respect, Tubenit

[eleventeen]

Few thoughts:

IMO your idea is far too ambitious. Again, I would suggest building up a populated AB763 (or other) parts board that would serve to drive virtually any output tube set you wanted. And get it working.


The VR tube will not vary in intensity unless it isn't being operated correctly.

[Paul1453]

I've read your post 3 times and simply don't understand what you are doing or what you are saying? 

Can you please post a schematic?   

With respect, Tubenit

A schematic will need to be developed as the build progresses.  I'll post a schematic for the first PP 6BQ5 amp when I decide which one I like how it sounds and has the potential to be modified into reusable sections for the other amps to use through the rotary switch. 
The other thread has this link:  https://www.ampbooks.com/mobile/amp-technology/6L6-phase-inverter/
Which may hold the key to using 6L6 tubes in a low power/low HV design.   

[Willabe]

A schematic will need to be developed as the build progresses. 

That is backwards.

And with 3 amps in 1, very complicated build. You need a road map.

You don't build a house and then draw up the blue print for it. 

[tubenit]

Paul 1453,

Willabe has this right.  PLEASE draw a schematic prior to starting on your amp.  Then post it here for responses and ideas.

I helped develop the Carolina Blues Special, HoSo56,  D'Mars,  Tweed BluezMeister and Tweed Overdrive Special (& quite a few other designs also).  (Most of those were done working in concert with DaGeezer).   

What it "seems like" you are possibly proposing may be more difficult then any of those amps?  I would have never attempted any of those successful builds without a schematic and a layout drawn PRIOR to buying parts and soldering.

My strong advice is to draw a schematic, post it and wait for responses from the forum.

With respect, Tubenit

[Paul1453]

Few thoughts:

IMO your idea is far too ambitious. Again, I would suggest building up a populated AB763 (or other) parts board that would serve to drive virtually any output tube set you wanted. And get it working.


The VR tube will not vary in intensity unless it isn't being operated correctly.

I understand your concerns, and will take a close look at the AB763 design.  Maybe that design could be the platform for driving the different output tube sets I envisioned.  If it requires a new PT and other parts I don't have on hand, then it might not be what I'm looking for.  On this build, I don't just want to make another amp.  I've got a number of other clone amps.  I want to try to make my own unique and creative design that incorporates other tried and true clone designs into my own ultimate rack mounted triple head design.   This will likely take quite a bit of time, research, testing, development, troubleshooting, etc.  Winter is coming soon, and I will have many dark and dreary hours to fill tinkering with my electronic stuff in the basement.  If it takes me until next winter to succeed in this endeavour I will still be happy.   The goal is to learn as much as possible, while creating something unique that I can be proud of.  I'm never going to sell this amp, if I do succeed.  It will give me great pleasure to set such a lofty goal and to work through all the trials and tribulations that it presents.  To be able to envision something like this and to ultimately bring it into reality will be a great achievement for me.  If I can't make this happen by next winter, well maybe then I'll have to go back to just making clone amps from my junk parts to sell, and I will have learned the limits of my imagination/abilities.  I really think this project is doable.  Is it practical, hardly.  Did we really need to go to the Moon?  No, but just look at all the advancements we made in technology thinking outside the box and chasing such a lofty dream.

[Paul1453]

A schematic will need to be developed as the build progresses. 

That is backwards.

And with 3 amps in 1, very complicated build. You need a road map.

You don't build a house and then draw up the blue print for it.

You have seen shows like OCC and West Coast Choppers, right?
Where they build unique and custom designed motorcycles.  There is no blueprint for the designs they build.  They take their understanding of basic motorcycle design, and whatever off the shelf parts they can use to make something totally unique from their imagination.  Kind of like that.  None of these guys were motorcycle engineers to start with, and at least I won't be speeding down the road at 100 mph when I discover a flaw in my design.

It's cool if this project seems far too ambitious for anyone else to be willing to work on.  In that case, I'll just have to work on it myself and bring specific design questions to the forum when I at least have part of a schematic for you all to look at.

Best regards,
Paul

[John]

I mostly just built little 5 watters for friends. I still wouldn't dream of starting even the simplest build without a good schematic and figuring the layout. For one thing, you'll be shocked how fast that enclosure fills up if you are thinking of doing what I'm thinking you're thinking. 


One of (IMO) the most crucial things to this hobby is documenting every thing you do with SCH (free program) or similar, shareable schematic program. In it you have all the basic symbols you need, you can create any symbol you need plus make parts -on a much cruder scale- like Sluckey does in Visio. True to scale. I enjoy spending the time figuring how to make everything fit most efficiently and "good practice" wise as I do building the amp. Just my 2 cents. :)

[John]

It's cool if this project seems far too ambitious for anyone else to be willing to work on.  In that case, I'll just have to work on it myself and bring specific design questions to the forum when I at least have part of a schematic for you all to look at.

Respectfully. That attitude won't get you the help you're looking for. You've just been given excellent advice by  very knowledgeable people (I'm not counting myself!). If you ignore it, they won't spend a lot of time helping you trouble shoot what could have been avoided.

[Willabe]

Where they build unique and custom designed motorcycles.  There is no blueprint for the designs they build.  They take their understanding of basic motorcycle design, and whatever off the shelf parts they can use to make something totally unique from their imagination. 

Their not putting 3 different engines on 1 frame. Their just riffing on the same theme. 

at least I won't be speeding down the road at 100 mph when I discover a flaw in my design.

No, but you will be messing with high DCV/DC current. That can kill you too.

[Paul1453]

Their not putting 3 different engines on 1 frame. Their just riffing on the same theme. 

No, but you will be messing with high DCV/DC current. That can kill you too.

I saw one sick design with 2 V8 engines on a motorcycle.

I was trained by the Army to repair Secure Communications Equipment to the component level.  The complexity of that circuitry makes most guitar tube amps look like childs play in comparison.  Granted I did not have free reign to redesign anything, but I think I have a pretty good handle on HV safety procedures.  Much of this gear employed multi-level rotary switches to change modes of operation.  It's really not that complicated if the designs incorporate a modular approach to the circuits.  You take the output of this module and redirect it through the rotary switch to the input of the next module and so on.  If a modular approach to the three different amps circuits is enforced, working out how to connect the correct modules through the rotary switch or switches is about the most complex part of the design.

How many people told Jimi Hendrix "Dude, you can't play a guitar like that!"   

[VMS]

 Position 3 a more Metal dirty sounding 6L6 amp.

For this sound I think you'll also need a dirty preamp.

Few issues you need to solve:

-Primary impedance of the OT so that every tube pair is happy.

-Do you turn off the unused push-pull pairs and how to do this. 

-If you leave them on, what is the total current draw and correct primary impedance in this situation.

[VMS]

Now that I think of it, you might have more success building 3 preamps into 1 poweramp.

You could do one preamp with noval tubes, other with octal tubes and third with 7-pin tubes.

 

[Paul1453]

 Position 3 a more Metal dirty sounding 6L6 amp.

For this sound I think you'll also need a dirty preamp.

Few issues you need to solve:

-Primary impedance of the OT so that every tube pair is happy.

-Do you turn off the unused push-pull pairs and how to do this. 

-If you leave them on, what is the total current draw and correct primary impedance in this situation.

Now this is what I would like to talk about.  Thank you VMS.

Yes the unused output tubes would need to be turned off.  Sticking to the modular design, I had actually envisioned an OT module and a separate output tube section module.  The 6AQ5s and 6BQ5s don't have any real issues using the same OT.  I was concerned that a single 6L6 SE would need it's own OT, and was considering where to place a 2nd OT in that case.  On my picture, I was thinking that if I needed another OT it would go next to the 6BQ5s where I tentatively made circles and put 6AQ5 in them.  Then the 6AQ5s would need to go in the other spot I marked for them, or the second OT could go there and then the tubes go back to the first spot.  It's just tentative now where anything other than the first 6BQ5 circuit will go.  The 1st amp, the BQ will make use of the already existing socket layout.

Then I found that link to the unique 6L6 output circuit configuration.  I haven't researched that in depth yet, but it did say something about a mismatched OT and it's performance as not being critical to this circuit design because it is purposely squandering the output power of the pair of 6L6 tubes.  It gave me hope that even a dual Class A PP 6L6 output tube module could still use the same OT module as the AQ/BQ circuits.  Much more investigation of this novel 6L6 output section is required.

[Paul1453]

Now that I think of it, you might have more success building 3 preamps into 1 poweramp.

You could do one preamp with noval tubes, other with octal tubes and third with 7-pin tubes.

I was kind of thinking about this type of approach before.  Mostly because of my lack of 12AX7 tubes.  Before I got this piece of gear I only had 1 unused 12AX7 and one I pulled from the preamp of my little Behringer AC108.  I kind of like this changing output tubes section idea better.  The 12AX7 tube is known as the preamp gain tube, and premium Mullards and Bugleboy 12AX7s prized as the sweetest sounding preamp tubes.  The ability to use my one premium Bugleboy 12AX7 in the preamp module of all three amps is quite appealing to me.  Having the same really sweet sounding preamp module that feeds into the three different output tube modules, will also allow an apples to apples comparison if someone was considering which type of output tubes they wanted in their more traditional single amp clone build.

[Paul1453]

Paul 1453,

Willabe has this right.  PLEASE draw a schematic prior to starting on your amp.  Then post it here for responses and ideas.

I helped develop the Carolina Blues Special, HoSo56,  D'Mars,  Tweed BluezMeister and Tweed Overdrive Special (& quite a few other designs also).  (Most of those were done working in concert with DaGeezer).   

What it "seems like" you are possibly proposing may be more difficult then any of those amps?  I would have never attempted any of those successful builds without a schematic and a layout drawn PRIOR to buying parts and soldering.

My strong advice is to draw a schematic, post it and wait for responses from the forum.

With respect, Tubenit

Sir, I do respect your experience and achievements in developing tube guitar amplifiers.  I get the fact that I need to have a schematic to work from.  My idea is that all three amp schematics are already out there fully developed and tested for me to use with only slight modifications.  I just haven't found the right ones to use yet.  Let's say for example I decided to use the Hoffman Blues Junior as the EL84 amp I want to use because it has the 2 EL84 and 3 12AX7 tubes I want to use in this design.  This particular design would not work with the PT or PS section I would like to use, but let's just overlook that for a moment and continue on with the example.  I would have a fully designed schematic to follow that I just needed to develop logical module parameters that could be enforced across all the amp designs.  Let's say I decide that my OT module parameters begin at the B+ CT connection and continue to the right on the schematic to the speaker jacks.  Then let's say I determined that my logical output tube module on this HBJ started at C15 and C16 and included everything between there and the Z connection on this schematic.  Then I continue to define my modules with the V3 section becoming a Master Volume/PI module.  The V2 section gets defined as my Tone Stack module with clear boundaries to where it begins and ends.  The V1 section gets defined as the input/pre gain module.  Now I have determined 5 logical module sections that when connected together become the HBJ EL84 amp.  If I continue to enforce these now defined module boundaries and definitions on the next already developed amp schematic say for a 6AQ5 design, I will have another amp broken into modules that I just need to connect together through my rotary switches.  Hopefully I will be able to reuse some of the modules from the first design.  Let's say I can reuse the input pre-gain module and the Tone stack module from the HBJ design.  Maybe all I need to make is a new Master Volume/PI module and Output tube module to have all the modules I need to connect to complete the second 6AQ5 amp.  For the third amp, maybe I get luck again and only need to make the output tube module and reuse and connect the other already existing modules through the rotary switch to complete this amp.  The reusable module sections significantly reduces the number of parts required to make three complete amps.  Another benefit of the modular design is that modules that work with one amp should not need to be troubleshot when reused in a 2nd or 3rd amps modular design.

Did I do a reasonable job of explaining my thought process behind this concept?    
I completely agree with your tag line "Life is a daring adventure or nothing at all!"
Maybe amp building could also be considered is a daring adventure or nothing at all!

[tubenit]

I would need a schematic to being to follow all of that.

With respect, Tubenit

[Paul1453]

I would need a schematic to being to follow all of that.

With respect, Tubenit

[tubenit]

The Hoffman Blues Junior doesn't sound like the amp you are planning to build. 

My suggestion is to post a schematic of the actual amp you are proposing to build that incorporates your innovative ideas such as octal & noval preamp and all the different power tubes with a topology of modular designs. 

Tubenit

[Paul1453]

The HBJ was used to illustrate the concept of modular design.  I am not proposing to use multiple preamp configurations.  On the contrary, I am proposing to identify three amp designs that are significantly similar enough to be able to reuse preamp, tone stack, and OT modules across all three amps.  Significantly reducing the parts needed to build three amp circuits.

Maybe someone caught a glimpse of what I was trying to explain and is able to do a better job explaining it than I did.   

Maybe if I leave tube amp schematics out of it, I can do a better job of explaining modular circuit design.  In secure communication equipment there is an encryption/decryption algorithm used.  This algorithm is broken down into logic modules.  If you are sending (encrypting) data or receiving (decrypting) data the same logic modules (which are actual electronic circuits) are used.  The same modules (electronic circuits) are used, only in a different order depending on whether to are you are sending (encrypting) data or receiving (decrypting) data.  This is the main concept I am trying to explain.  The reuse of electronic circuits that already exist in your equipment.

If I have a fully functional preamp circuit existing in an amplifier, why can't I just reuse this circuit when adding a different output circuit?     It works in Army Commo gear.

[printer2]

Do a block diagram of what you want to do. Figure out what sounds you want, what amps you are trying to get the sound of. Just making something complicated because it is cool is not a good way of starting something. Break up your thoughts into paragraphs rather than one continuous stream of thought. We are not on the same wavelength as you.


I could do what you are thinking, a number of other people on this forum are also. No offence intended, don't think you understand the magnitude of what you are contemplating. Think of each amp section you want as either a transmitter and receiver, all doing both at the same time in a confined space. Even if you have a proper design in schematic form the layout could make or break it. From my brief snapshot of your posts, don't think you are there yet. But what the heck, your life.


What amp sonics do you want, no question of what output tubes. Speaking of output tubes, funny how some people will make an 18 Watt with EL84's, change a couple of resistor values in the PI, run 6V6's, and both versions sound pretty close to the same. Just saying.


Wanting to use the same tube shared between different circuits. Much cheaper and easier to get another tube and make a separate circuit for it. Have gone down that road myself, done it, but it ain't easy. Another person like my idea and did it himself, he could not get rid of the HF oscillations he had and could only turn up the gain to half. He could not see the invisible components.


I would say make a basic amp, one set of output tubes and use the preamp send/return in order to insert different clipping/distortion circuits. Could be tube, SS, overdrive a transformer, whatever you want. Have a six position switch with a different sound for each module, knobs to twiddle around in each module. You will probably learn more than just taking pieces of existing designs and trying to mate them.

[shooter]

why can't I just reuse this circuit when adding a different output circuit? 

You can, that's what I have done 14 times, resulting in 4 *usable* amps. plexi with matchless, fender with Gibson, Marantz with bogen..........BUT when I did this I 1st found a handful of schematics, studied them, solved  the layouts, stitching, impedance, power, and all manner of *issues* before I ever ordered anything.

[Ed_Chambley]

What amp sonics do you want, no question of what output tubes. Speaking of output tubes, funny how some people will make an 18 Watt with EL84's, change a couple of resistor values in the PI, run 6V6's, and both versions sound pretty close to the same. Just saying.



This is a great quote!!

Each tube has different distortion characteristics, even EL84's compared to other EL84's.  For instance RCA Pan getters have a raspy tone when compared to Amperex when using a ceramic speaker, but use a Celestion Blue and both mellow out.  What I am saying is a "special" circuit does not always deliver what we want.  Think of all those amp designers who came before us and the ones currently doing it.  They all know a lot and using their ideas does help.

Not naming any names, one moderator rode my butt until I began drawing schematics.  The guys are asking for one.  Why not just download a bunch of the editable .sch files that have the "Modules" you are looking for.  I am sure someone has done it.  Open another instance of Express and just copy the modules you want to a new file and post.  If it has errors someone will help get them out.

The last one I posted I had V2b's grid grounded which would make for a quiet amp.  Just get something started and you can do it in module form.  I do it all the time.  For instance, K gave me a loop to try in a high gain amp and I redrew it in Visio as my loop module.  Now anytime I want to add a loop all I have to do is separate the area I want to insert the loop in a new schematic, and copy and paste.

Also, nothing wrong with using a pencil and paper.  That is how I made a quick schematic of the Carr Rambler when I had on I was servicing.  I now have a Visio file of it, with the loop.  I probably will make a layout for this one, just have not had time. 

I even have printed and pasted different sections together like when I built a Plexi Preamp to a Chieftan power section.  I wanted a cathode bias EL34. 

[Paul1453]

With a little help from Willabe, I realize I was asking all the wrong questions.   

  This is still just a concept now, so I should have asked: 

Could anyone point out some low power 280VDC or less B+, PP EL84 and 6V6 designs I could investigate?  Fender, Gibson, etc. model #?

It would be great if these low power designs had the same (12AX7 tubes) in the preamp/gain, tone stack, and PI sections or are at least very similar.
If not, at least some well known low B+ EL84 and 6V6 PP designs for me to look at would be a start.

Could anyone point out some Power Supply designs that used the 0D3 tube or tubes?

I know these designs are obsolete, but it's kind of like I want to put shag carpet upholstery in my low rider because I think it looks cool and makes my car unique. 


I will work on a block diagram to start with to post here.  That should help. 
I will use this, and the proven design schematics you hopefully help me find, to develop specific schematic segments that go in the block diagram sections. 
As this progresses, I will then be able to begin assigning appropriate wiring connections to the rotary switch/switches. 
Making sure this complies with the block diagram layout, to progress through the circuit modules and rotary switch/switches to complete each individual amp.

With a little help from you guys, 

I should be able to create a full and complete schematic diagram of my proposed triple header amp before I start soldering anything together.

Does that sound better to you guys?

I am sorry if I upset any of you, or gave you the impression I did not respect or value your knowledge and experience.

Would any of you still be willing to work with me and point me in the right direction?

I would be extremely grateful for the help, and try my best not to upset you any more.  OK? 

[PRR]

> Power Supply designs that used the 0D3 tube or tubes?

For guitar amps? No. Why would we want to regulate a g-amp? More-more-MORE!

There were a few HI-volt PA amps which used a gas tube to "anti-regulate" the screen supply. These ran the plates much higher than the screens needed to be. The gas tube dropped the voltage. If the amp were over-loaded so bad the plate supply dropped, the screen supply dropped relatively more. This set some limit on how bad the amp could hurt itself. I think the "benefit" was slight, the cost non-trivial, and it is NOT what we want in a g-amp.

Your gas tube is an over-grown Pilot Light. It needs >185V (better give >200V) through a resistor big enough that it can NEVER pass more than 40mA. As 40mA is a heavy added load on most small amps, you might better aim for 15mA-20mA. Need to stay over 5mA or the glow will go out. Given a 300V raw supply, and 150V across the lit tube, (300V-150V) at 15mA is 10K at 2.25W, use a 10K 10W resistor.

If you drop and break it, open the windows and get out for an hour. The gas is NBD, but there is a trace of radioactive to help start the glow. Then sweep it up with minimum fuss into a plastic bag, into a box, and take it to Hazardous Waste. Tell 'em it is a smoke alarm (similar radioactive trace, and they won't know an 0D3). 

[Willabe]

......some well known low B+ EL84 and 6V6 PP designs for me to look at would be a start.

Look at this;

http://el34world.com/Forum/index.php?topic=19413.msg200905#msg200905

[Paul1453]

Thanks, I was kind of watching this thread and had written Kustom 15 in my notes from another search.  Unfortunately it appears to use a higher B+ than the PT currently in my rack mount case can provide.  The current PT is quite beefy and has 2 6VAC supplies in it to power all the tube heaters this concept amp might require.  It just doesn't have that 400V+ HV source many guitar amps like.  If I wanted to try to swap it with Big Boy or Little Boy, the still not completely identified PTs from my junk gear thread, either one of those appears to have the muscle to push a 400+V B+.  I still haven't identified all the secondary windings on the Boys yet.  That might be an option for me to consider though.

[VMS]

AX84 site has got this comanchero project that is low voltage. Preamp is unusual but there is building blocks section with different preamps:

http://ax84.com/associateprojects.html

http://ax84.com/corepreamps.html

[Paul1453]

Some measurements show that I could put the Big Boy PT in the rack case, not by much and it would require me to remove the metal plate and cut a hole in it for his leads to go through.  On the bright side though, that would remove all B+ power restrictions.  Looks like I could get a B+ of +468V with a tube rectifier, and +546V SS.  That would give me a B+ high enough for just about anything.  Maybe a little too much, or just the thing needed to dump voltage with my stupid purple light tubes?

[Willabe]

Looks like I could get a B+ of +468V with a tube rectifier, and +546V SS. 

WAY too much for EL84's and 6V6's. 

[Paul1453]

Looks like I could get a B+ of +468V with a tube rectifier, and +546V SS. 

WAY too much for EL84's and 6V6's. 

Little Boy fits easily, but still needs a hole made.  He can do +375 tube and +440 SS. 
It's beginning to sound like I might even need some switching capabilities built into the PS for this goofy concept to work.  Hmmm. 

There is quite a bit of room to work with inside this rack mounted case.  Probably twice as much room as any other normal head amp.  It has the added benefit of being able to keep all the PS components in their own shielded compartment, separate from all the signal handling components.  This thing was specifically designed for measuring random signals in lab conditions with replicable results, so it does have that going for it.

[Willabe]

Little Boy fits easily, but still needs a hole made.  He can do +375 tube and +440 SS.

That's still way too high for EL84's. Can you tell us how your getting these B+dcv's?   

It has the added benefit of being able to keep all the PS components in their own shielded compartment, separate from all the signal handling components.  This thing was specifically designed for measuring random signals in lab conditions with replicable results, so it does have that going for it.

That can be a good thing, but in most guitar tube amp builds, IF laid out right with good lead dress and with a good grounding scheme it's not needed.       

[tubenit]

You need to check the volts and ma capacity on your PT and then compare with the tube data sheets to see what each tube can handle in
volts and what the current draw will be.

IF you have a 275-0-275 PT with 150 ma or a 300-0-300 PT with 150 ma, then you can do this:

5Y3GT rectifier       300 X 1.1 = 330 volts    OK for EL84's or 6V6's
5V4                       300 X 1.2 = 360 volts    OK for 6V6 or 5881/6L6
GZ34                     300 X 1.3 = 390 volts    OK for 6V6 or 5881/6L6
solid state rectifier  300 X 1.4 =  420 volts   OK for some 6V6's  or 5881/6L6

OR 

5Y3GT                   275 X 1.1 = 303 volts    barely OK for 6AQ5, barely OK for 6K6,  EL84, 6V6 ..... etc.....

I've attached a tube cheat sheet with data about tubes that may be useful IF you are going to pursue this.

With respect, Tubenit

[tubenit]

The idea of different modules has been done before:
 
http://el34world.com/charts/Schematics/files/seymour_duncan/seymore_duncan_modules.pdf

http://www.seymourduncan.com/forum/showthread.php?174820-Seymour-Duncan-Convertible-amp-modules

My understanding is that these modular amps were not very reliable.

with respect, Tubenit

[Paul1453]

Thank you for the information, Tubenit.

That data sheet is helpful.  Just by looking at the tubes I would have never guessed the 6X5 is wimpier than an EZ80.  Any reason for the 5V tubes being able to deliver more current? 

I think I'm starting to understand the idea behind Mesa's Dual Rectifier. 
We like the tube rectifier sound but we need more power!  What can you give us engineering?

I had no idea anyone had ever offered a modular amp on a commercial basis.  That idea had to come from a ding-dong in management, like me, and not from the engineering department.  Unreliable, I'd bet that is right.  Connectors are always a source of problems.  You want Joe Six-Pack to be able to swap in and out different modules to be able to change the sound of his amp?  Hell, we'll have to key these connectors differently just so he can't put the wrong modules in the wrong place and blow the whole amp up.  I can imagine lots of issues needed to be addressed before they ever offered this to the public.

If my concept ever does become a reality, looking less and less likely, at least the modules would all be secured in place and never changed around by Joe Six-Pack. 
I was somewhat concerned about the reliability of a rotary switch to do that job.  Keyed connectors would be a nightmare.

Willabe, I was getting my possible B+ from taking the secondary VAC and multiplying by 1.2 tube and 1.4 SS.  I learned that here, probably from someone like Tubenit. 
That sheet he posted is great! and has more in-depth info.  I've got it saved on multiple computers now.
When you asked that question, I thought I might of been having a senior moment and incorrectly recalled this info from my rapidly ageing memory.   

[printer2]

Hate to say it again, ignoring your build what kind of amplifiers would you like to play through? Where will you be playing it? Once you decide that you can work around the parts at hand.


As an example, say you like a clean Blackface sound, if you like it loud there might not be enough in the PT to get you there. But what if you like a distorted flavor, much more output. Two examples I can see coexisting is the 5E3 Deluxe and the 18 Watt. Comparable voltage at the output tubes, 8k OT works for them both also.


But what if you want an amp that runs off more voltage than you have? Thankfully we have VVR's we can plop into those amps. How does that help you? The amps still sound like themselves when the voltage is turned down (within reason). So you have an amp that runs off of 450V but the VVR drops the volume a bit and you measure what is at the output tube plates. Wow, who would have thought 325V could still kick ass with EL34's? Why does the amp still sound like itself? It still has the same gain structure and the stages more or less clip in the same relation to each other.


Now why do our amps sound like they do, baring the use of the 'proper' caps? A lot use the 12AX7 and they can sound different. It is the architecture of the amp as well as the parts. Just because You have a Princeton cathodyne instead of a plexi LTP you are not going to sound like a Fender. This is why I see mix and matching different stages work best when you actually adjust them to work together. Change the 49k (i think) resistors in the Princeton's PI to 100k and you get more signal swing. Depending on the output tubes one may work better than the other depending on how you want the combined circuit to behave.


Lot of ways to skin a cat, some are more efficient and easier than others.

[Paul1453]

Even if this concept ends up getting abandoned on the drawing board, it will have proven to be a valuable training exercise for me! 
Organizing, Planning, Diagramming, Documenting, and Detailing work are valuable skills directly applicable to my career as a manager/supervisor.

Thank you for steering me onto this course of action, instead of allowing me to try to fly by the seat of my pants.   

Attached is a simple block diagram to start with.  It will likely need some revisions, but it will at least provide a general framework that helps me to direct my efforts to fill in the details.

I envision color coded power and signal lines being added connecting modules.  Color coded amp modules being added to the general module boxes.  Then specific schematic segments being put inside the color coded amp modules, with details of power and signal connections documented in the schematic segments.  If done properly, this could be developed into a full and complete schematic diagram of the proposed highly complex amplifier.

[Paul1453]

I generally just practice guitar/bass using Rocksmith 2014 on my computer.  Little 5W bedroom amps are usually enough for me when I want to plink around on my guitar in the basement.  The only reason I'm looking at around 15W PP output designs is in case I meet some real players who want to set up a drum set and bass amp in my basement for a weekend beer drinking jam session.  Little 5 Watters would likely get drowned out by a drum set and bass in such a confined space.  I don't have much experience with specific amps to say I want this design or that.  No dreams of becoming a gigging musician for me.  Just someone who likes to have fun messing around playing music.

[printer2]

A couple of different versions of block diagrams.