Introducing "The Kitchen Sink" submini amplifier

[Ripthorn]

So I have been working on a little submini amp, and as the ideas have come along, the project has ballooned.  Thus the title, this thing can do a lot.  It has a clean channel, dirty channel, triode boost (pre-clean/dirty) with bright switch, switchable tone stacks, fat and presence controls, master volume, dual power amps (high and low power), line out, line in, cab simulators, footswitchable channel and boost, and tone stack bypass.  This has taken a long time to come together, and there are still details to be worked out.  I do have the preamp and tone stacks all worked out, so I thought I would post some clips.  I have six clips, they are clean, slight grit, clean with boost, moderate grit, kind of a vintage high gain sound and then a modern high gain (boosted dirty channel).  Let me know what you think.

All of the clips were recorded PRS CE24->PODxt for cab sim and a little reverb(babies in bed is not conducive to miking up a cab)->Presonus Firepod->N-track studio.  No post processing.  The background noise is probably a function of how high the gain is and the fact that I have carbon resistors and it is on the breadboard.  Please forgive the sloppy playing, these were done really quick.

http://www.filehosting.org/file/details/21499/tube_amp_clip_dirty_light.mp3

http://www.filehosting.org/file/details/21498/tube_amp_clip_dirty_boost.mp3

http://www.filehosting.org/file/details/21497/tube_amp_clip_dirty.mp3

http://www.filehosting.org/file/details/21496/tube_amp_clip_clean_grit.mp3

http://www.filehosting.org/file/details/21495/tube_amp_clip_clean_clean.mp3

http://www.filehosting.org/file/details/21494/tube_amp_clip_clean_boost.mp3

[waltk]

Hi Brian,

I didn't hear the clips, but I'm totally awestruck by the magnitude of your accomplishment just from the description...  I'm sure you'll be posting some pictures tomorrow (lol). 

[Jered]

   Sounds interesting. So which subminis did you use for pre and power amp?  Are you going to post a schemo?

[waltk]

OK.  So now that it's today, and not yesterday, give it up - an April fool's thing right?

[Ripthorn]

This is no April fools, I have spent the last couple months exclusively on this project.  There are probably even a few options that i forgot to mention, I just can't think of them right now.

Jered - I am using two 6021's and one 6111 for the preamp and the power amp will be two 5902's in a/b pp for the high power and the low power will either be the 5902's in class a pp or two 5672's in a/b pp.  The preamp is actually based off the schematic you posted in the "inspired by the valve caster" thread, though I have taken some liberties with values and some part locations, etc.

I will be posting schematics over the course of the next several days or so (I still have to make sure they are current).  Since it is such a big project, I have separate schems for booster, clean pre, dirty pre, power amp, tone stack, phase inverter, etc.  Hope you enjoy this thing as much as I do.

Sorry about the bad links, let's try these:

http://www.mediafire.com/file/1dozuzdmgci/tube_amp_clip_dirty_light.mp3

http://www.mediafire.com/file/yjdgidzz1tg/tube_amp_clip_clean_boost.mp3

http://www.mediafire.com/file/o2ygnvxtjon/tube_amp_clip_clean_clean.mp3

http://www.mediafire.com/file/jernmho0nkz/tube_amp_clip_clean_grit.mp3

http://www.mediafire.com/file/zzxijddyozn/tube_amp_clip_dirty.mp3

http://www.mediafire.com/file/ttzndhtzzma/tube_amp_clip_dirty_boost.mp3

[kurtlives]

Can host the clips somewhere else, maybe here?

You have to enter your e-mail adress for each clip individually, then it sounds you a link to your email. Then the link isn't working for me and I am getting jumbled text.


Wanting to hear this!

[ayayay!]

Yeah, I echo kurtlives.  Try www.box.net.  It takes 5 minutes to set up an account, uses a free player... super simple, fast & easy. 

[liddokun]

Sounds fantastic. Can't wait to see pics and schematics!

[waltk]

This is no April fools, I have spend the last couple months exclusively on this project.

OK. Then I really am awestruck!  Heard the clips, and can't wait to see more details...

[jacobyjd]

Wow, that's really impressive--I'd be curious to hear it pushing a speaker cab.

I especially liked the clean and clean + boost clips. If I could build a studio amp that would sound like this and have it still be pretty small in its form factor, I'd order the parts today

Any chance of seeing your schematic? 

[Ripthorn]

Wow, that's really impressive--I'd be curious to hear it pushing a speaker cab.

I especially liked the clean and clean + boost clips. If I could build a studio amp that would sound like this and have it still be pretty small in its form factor, I'd order the parts today

Any chance of seeing your schematic? 

The schems will come up in the next few days, I just need to make sure they are all correct before posting.  Just as a note, the clips are running at 34V, but there is a ton of umph in this thing.

[jacobyjd]

Even more impressive--which only makes me wonder what higher voltage will do to what is already pretty nice tone...

[Ripthorn]

I have tried it at 74V and though the background noise is higher, the tone tightens up more, but still maintains its character.  I plan to have a switch in this thing that will allow the tubes to run at 120V or thereabouts or at about 24V.

[jacobyjd]

Ok--very cool prospect. do you just use a 1:1 transformer to run it at 120v? I'm kinda new to amps...

[frequencycentral]

I'm so glad you project is nearing completion Brian, it sounds really interesting - but I can't seem to access those soundclips! Frustrating!

[Ripthorn]

I'm so glad you project is nearing completion Brian, it sounds really interesting - but I can't seem to access those soundclips! Frustrating!

Thanks for the kind words Rick.  For sound clips, try my post further down with clips (it won't let me modify my original post and remove those clips).

[punkin]

WOW! Very tasty sounds. I'm sitting on the edge of my seat waiting to see that build. 

[sean k]

Like they said back in the late fifties when the first germanium transistors were appearing...

"Sub mini tubes are the way of the future"

So your class A p/p output is just biasing way hot?

[Ripthorn]

Like they said back in the late fifties when the first germanium transistors were appearing...

"Sub mini tubes are the way of the future"

So your class A p/p output is just biasing way hot?

The clips above are just the preamp, the power amp still has yet to be tweaked and tested.  I have not decided if I am going to do class a pp or if I am going to do some other scheme for "low power".  I am actually thinking I might either do a separate power amp using 5672's or just feeding the 5902's less voltage before I try a class a pp.  But from what I understand, you can run a class a pp by just not having cathode caps to ground in your normal class a/b pp.

[Ripthorn]

Alright, as promised, some schematics.  This first one is for the triode boost section.  This is switchable with a dpdt relay in front of the regular preamp (so that it can boost either clean or dirty pre's).  You'll notice the abnormally high plate resistor of 390k.  This is what i had at the time.  I have tried it with 220k, but can't hear too much of a difference on the end tone, so I have left it as is.  The 470k series resistor (R3) at the end is so that I don't overload the first preamp stage (it creates a voltage divider with the pulldown resistor so that it doesn't load it down too much).  Yes, it should be 470k.