Ultraphonix from hell

[rootz]

Lately I've been tinkering a bit with some Ultraphonix circuits floating around here. I quickly got the idea to build an amp of some leftover parts and experiment a bit with ideas borrowed from Dumble and Taylor Cox. Taylor build the Ampliphonix & gain amps.

Design goals:
- Having fun designing something new and exploring things I haven't done before!
- Inspired by Dumble/Ultraphonix designs;
- Switchable tube and SS rectifiers;
- Switchable fixed and cathode bias;
- Suitable for low volume, so no need to drive the power amp;
- 2 channels with boost;
- Fluid lead tone, bright spanky cleans;
- Reverb;
- Maximum of 5 preamp tubes.

I took the Ampliphonix & gain mk1 as a starting point. This seems to be an amp with 2 fully independent channels. One being clean, the other a form of Ripper; 3 gain stages + cf and Marshall stack.
There is one thing about 3 gain stage + cf amps for leads to me: I almost exclusively like them when used in conjunction with power amp distortion. It seems to me that less stages just provide too little options for frequency and tone shaping to get to my design goals. So I went 4 gain stages + cf, with the first triode shared with the clean channel. The second gain stage is switchable, so it easy to get a rawer and brighter crunch out of the preamp.

I use a one tube reverb with an ECC81. This one needs some more refining for sure. Just not much reverb and I do not really like the reverb I hear yet.

But I was kinda surprised by the rest of the amp. I certainly am going to take this one to some gigs once I've ironed out some wrinkles.

Here's some pictures and of course a nice low quality low volume iPhone recording. But you get the idea. Foot switch blue led is channel switching, yellow one is for boost.

[dcribbs1412]

Outstanding!
Fine sounding amp Rootz.

D

[Guy77]

This sounds amazing Bas! The drive on this amp sounds like a Marshall amp with the Marshall (Bassman) cathode follower driven tone stock.
This sounds like a very fast amp. I like it. Will there be a schematic?

Thanks for posting.

Cheers

Guy

[erwin_ve]

Bas; you got a wrong title: Ultraphonix from heaven.

Really good sounding !

Erwin

[Bombacaototal]

Great project, very cool ideas and sounds amazing

[10thTx]

Very nice sounding amp! Thanks for sharing. I would also love to see a schematic for your design, please.

with respect, 10thtx

[Reeltarded]

Sounds fantastic! You got a lot out of what there is in there!

Funny enough, I have a similar thing in process right now, but it doesn't have reverb and it cascades UP through an ODS section and includes an au7 stage before everything with tons of boosts and cuts for bright and coupling selection.

Your amp is exciting!! Whoosh!

[bepone]

very nice,

It seems to me that less stages just provide too little options for frequency and tone shaping to get to my design goals.

nothing strange, it IS like that! more stages, more tone shaping, more quality in the drive! the same is valid for the clean.
lets go back to 80'ties, Soldano SLO 100 is the top of the tops, so if you want to add some cold clipper stage, will be even better

Here's some pictures and of course a nice low quality low volume iPhone recording. But you get the idea. Foot switch blue led is channel switching, yellow one is for boost.

iphone recording quality is not low, you can use it for profi purposes too

now i saw regular Mouser parts inside, but from where are the trasnformers?? always good info to "put in the book"

[beasleybodyshop]

I spot some LCA dralorics and a handful of other "correct mojo" parts as well! Build looks and sounds great!

[rootz]

Thanks for all the kind responses!

I’m not going to share a schematic yet. I think i laid out the general concept pretty well. The fun part is that anyone can build amps like this one, really. There is hardly anything new. Might do a block diagram, but word is busy, so don’t expect it to be ready over night.

There are not many mojo parts in the design. No Dralorics. There are Xicon Little Rebels, Koa Speer CF1/2, Dale’s, I believe the bigger carbon film resistors are Xicon too. Coupling caps CDE DME and an occasional 6PS early in the amp, 716P’s and a leftover SoZo in the PI. Makes for a rather fast and bright amp. I love those DME’s for many things. Tiny so you van fit them anywhere and bright, but not harsh. Ceramics are Vishay X5f and CG0, most Mica’s are CDE. I don’t like mica’s, but it was the only thing I had.

The Marshall sound is down to the CF and stock Marshall values in the tone stack. Deviate from those values and you deviate from the Marshall sound.

What I really like about the ODS circuit is the centre biasing of the preamp tubes. It does have a specific tone. To me it sounds more defined and brighter than cold clippers. Keep in mind that to obtain the sound qualities of an SLO you also need that double CF arrangement IMHO.

An idea I’d like to try Bepone, is the cold clipper arrangement in the JVM410. In those the anode resistor of the third gain stage is split by means of a switchable cap to mass. Cap in leads to a small anode resistor and thus clod clipping stage. Mind you, gain drops significantly by doing so. But it is an otherwise fun concept.

Bepone, the power transformer is from Marble amps in The Netherlands. Custom wound with dual secondaries, 5V @ 5A, 6,3V @ 7A, bias tap, winding for relais. A little thicker than Bassman sized Hammonds, but otherwise the same size. Really good PT for projects. The OT is a 40yo Drake 784-139 from an 2204. Choke is a Hammond 194A Iirc.

Not complaining about the quality of the iPhone, but the fact the the squeaking of my chair is louder than the amp speaks volumes.

You should hear the amp via my newly designed reactive load and cab m+

[bepone]

An idea I’d like to try Bepone, is the cold clipper arrangement in the JVM410. In those the anode resistor of the third gain stage is split by means of a switchable cap to mass. Cap in leads to a small anode resistor and thus clod clipping stage. Mind you, gain drops significantly by doing so. But it is an otherwise fun concept.

this im using in h-ifi, when the gain is too much and i just need to use this tube, just take signal from the other tap, anode resistor split in 3 in series, and just reconnecting

Bepone, the power transformer is from Marble amps in The Netherlands. Custom wound with dual secondaries, 5V @ 5A, 6,3V @ 7A, bias tap, winding for relais. A little thicker than Bassman sized Hammonds, but otherwise the same size. Really good PT for projects. The OT is a 40yo Drake 784-139 from an 2204. Choke is a Hammond 194A Iirc.

Not complaining about the quality of the iPhone, but the fact the the squeaking of my chair is louder than the amp speaks volumes.

You should hear the amp via my newly designed reactive load and cab m+

aaa you have most important part correct! OT, this is cheating now you can do anything with the components always will sound good!
i just scored old bassman 100W Schumacher OT, can't wait to put this in one of the 100 Watters!

i dont have reactive load, but somewhere is in plans.. i'm targeting to amp sounds good at ,lets say loud but not too loud , cca 10-15W already, so neighbours can live with that one day will come also this project......too much things to do

[10thTx]

I’m not going to share a schematic yet. I think i laid out the general concept pretty well. The fun part is that anyone can build amps like this one, really. There is hardly anything new. Might do a block diagram, but word is busy, so don’t expect it to be ready over night.

I can appreciate being busy and not being available or ready to share a schematic. I'm grateful for what you have already shared. Thank you! Especially your most excellent soundclip.

I am quite curious about the topology (layout) of the triodes in your design? Part of my curiousity is connected to that quest for great overdrive at a low volume & from what I hear from your soundclip, it seems you have been successful with that.

I am presuming this DRAFT Wild Guess schematic is FULL of ERRORS .................... So, what I am asking is whether the triode topology itself is laid out correctly in the schematic? IF you are willing to share that one piece of the puzzle? I am assuming there are too many errors in the component values and layout of the components in between the triodes to have this draft schematic to be useful in making a build.

Can you confirm just the triode topology is headed the correct direction in this draft drawing, please?

IF you would like at some point to share a schematic, the SCH schematic is attached and it is editable. You can use that as a starting point as the SCH program is easy to work with if you'd like to take that approach? AND ...... it has a 2nd page with the PT and B+ rail drawn out that can also be edited.

EDIT ................ 1st DRAFT schematic was incorrect with triode topology and is now deleted.

Respectfully, 10thtx

[Reeltarded]

Can you confirm just the triode topology is headed the correct direction in this draft drawing, please?

Respectfully, 10thtx

In OD mode V1A is the first triode and it jumps everything ahead of the switch. V1A is the head of both channels.

44DAF7C1-CC72-4A3F-81D9-5C32DE8457F5.jpeg

[10thTx]

EDITED and new revised DRAFT wild guess is on 2nd page of this thread.

With respect, 10thtx

[rootz]

An idea I’d like to try Bepone, is the cold clipper arrangement in the JVM410. In those the anode resistor of the third gain stage is split by means of a switchable cap to mass. Cap in leads to a small anode resistor and thus clod clipping stage. Mind you, gain drops significantly by doing so. But it is an otherwise fun concept.

this im using in h-ifi, when the gain is too much and i just need to use this tube, just take signal from the other tap, anode resistor split in 3 in series, and just reconnecting

Bepone, the power transformer is from Marble amps in The Netherlands. Custom wound with dual secondaries, 5V @ 5A, 6,3V @ 7A, bias tap, winding for relais. A little thicker than Bassman sized Hammonds, but otherwise the same size. Really good PT for projects. The OT is a 40yo Drake 784-139 from an 2204. Choke is a Hammond 194A Iirc.

Not complaining about the quality of the iPhone, but the fact the the squeaking of my chair is louder than the amp speaks volumes.

You should hear the amp via my newly designed reactive load and cab m+

aaa you have most important part correct! OT, this is cheating now you can do anything with the components always will sound good!
i just scored old bassman 100W Schumacher OT, can't wait to put this in one of the 100 Watters!

i dont have reactive load, but somewhere is in plans.. i'm targeting to amp sounds good at ,lets say loud but not too loud , cca 10-15W already, so neighbours can live with that one day will come also this project......too much things to do

Yeah, that OT was a very lucky score! So are the NOS Tesla power tubes. I'd love a nice old Schumacher OT, but these are very hard to come by in The Netherlands.

I just build a new reactive load. It is based on the Suhr reactive load, but modelled after my own speakers and cabinets. I added a deep switch that switches the low end resonance from 110Hz to 75Hz. That is closed to open back. And there is a high cut switch that switches off one inductor in the high end. I'd gladly share the design if you're interested. Build in a box only measuring roughly 20x20x8 cm. It kills when paired with something like a Two Notes C.A.B. M+.