PT recommendation...

[FuzzFaceBuilder]

Hi Everyone,
I need help with deciding on a PT for a custom project I'm cooking up. It's a daunting task for me to get an amp build going, as I'm in my first year of school for an EE degree. And tube tech is not taught in as much detail as I'd like.

The build is a 100w Slidewinder(5F6-A)/Ultra-Phonix/JTM45-100 hybrid w/reverb. It'll be build over a longer period of time as I'd like to take the build slowly. It'll have a Fresh Fuzz op-amp overdrive on a relay as well as the standard "tone stack defeat circuit" (PAB).

The specifications
OT: Modified 5F6-A circuit/PAB/passive loop/op-amp input/Reverb
PT: 100w/4-6L6's/SS rectifier/4-8-16 taps

I'm aware that this is quite the build for a first "solo" attempt (built a 5E3 and worked on an early SF Twin, the non UL ones, with a friend), and I've had quite the time going through the forum/posts looking up information for the build. I'd like to be a contributing member as my education grows, and want to say thanks in advance to everyone.

Looking forward to your suggestions,
Hale

FWIW, I know that this build counters a lot of HAD'S gain structure AND tone philosophy, but I'd like to "approach" it as HAD might have if he built a Dumble-ized JTM45/100 reverb.

[heisthl]

OT: Modified 5F6-A circuit/PAB/passive loop/op-amp input/Reverb
PT: 100w/4-6L6's/SS rectifier/4-8-16 taps

FWIW, I know that this build counters a lot of HAD'S gain structure AND tone philosophy, but I'd like to "approach" it as HAD might have if he built a Dumble-ized JTM45/100 reverb.

He kind of did - the Bluesmaster. Where does the JTM45 come in to the picture? Do you intend to use a cathode follower ahead of the tone stack (5F6-A) and the JTM45 PI? Showman iron is always good for 100watt 6L6.

EDIT: OK - made me look down memory lane - the JTM45 and the bassman are identical except 12AX7 instead of 12AY7 and minute value differences in the tone stack and PI (and the GNFB). The mind is the second thing to go..... I forgot what the first is.........

[FuzzFaceBuilder]

Heisthl,
Thanks for the response! You had me worried for a bit with that PI question. I thought they looked the same (for the most part) in the schematics.

The Showman iron is good for the project! Thanks for the heads up!

The Bluesmaster is an HRM with a cathode follower PI if I understand correctly? (Please correct me if I'm wrong).

Thanks again,
Hale

P.S. I have Concept Draw (a Mac guy ) under the tree so schematic/layout will be up soon for perusal/approval. Although I've heard the learning curve is steep.

[heisthl]

[quote="FuzzFaceBuilder"]Heisthl,

The Bluesmaster is an HRM with a cathode follower PI if I understand correctly? (Please correct me if I'm wrong).

,
Hale

To my limited knowledge the Blues master has a different tone stack than an ODS and a PI like a marshall - no cathode follower.

[dave g]

The Bluesmaster is basically an HRM with a Marshall PI and a Fender/Marshall hybrid tonestack. mdroberts1234 drew up a very nice schematic here:

https://tubeamparchive.com/viewtopic.ph ... 4&start=75

I don't believe this circuit is 100% "kosher" per-se, but it does sound great. There really aren't enough known BM amps out there to establish a set of benchmark values.

Dogears would know better than me.

Just out of curiosity, why bother with an op amp driven fuzz circuit inside a tube amp, especially when it's just as easy to build a tube overdrive circuit? IMHO putting a solid state clipping circuit in the amp completely defeats the purpose of building a tube amp in the first place...YMMV.

[FuzzFaceBuilder]

Hey,

Hale

To my limited knowledge the Blues master has a different tone stack than an ODS and a PI like a marshall - no cathode follower.

Thanks for the info! I'll be sure to dig around some more to make sure I'm not trying to "reinvent the wheel".

The Bluesmaster is basically an HRM with a Marshall PI and a Fender/Marshall hybrid tonestack.

Just out of curiosity, why bother with an op amp driven fuzz circuit inside a tube amp, especially when it's just as easy to build a tube overdrive circuit? IMHO putting a solid state clipping circuit in the amp completely defeats the purpose of building a tube amp in the first place...YMMV.

Thanks for the heads up on the HRM Bluesmaster thread/info. I'm building this amp as a platform for fuzzes and a ring modulator much in the way Eric Johnson/Hendrix and Jan Hammer/John McLaughlin would (respectively). The op-amp fuzz would just be a personal thing, as the tone I'm going for with this amp often had that op-amp circuit in front of it. It's in no way as beautiful sounding as a tube OD circuit, to be sure. As for the final say on it, I might just use a regular FET board, if the initial combination doesn't work too well.

Thanks again,
Hale

P.S. I'd appreciate any other help/recommendations you could throw my way!

[Normster]

I built a mongrel amp several months ago that used a CF to drive the post-OD tone stack. Not sure what I was going for, I just had a few ideas I wanted to try out. It worked, but wasn't something that I felt like investing tweak-time in. (I yanked the board and converted it to a bluesmaster.) I guess I was hoping for something a bit more blackface in the cleans and JTM45-ish in OD, but it didn't do either one particularly well.

[dave g]

I guess I was hoping for something a bit more blackface in the cleans and JTM45-ish in OD

I think that sums up the Bluesmaster pretty well

[talbany]

Norm
Do you mind posting this layout in a Visio.. Not for the amp but I see some very cool Macros that might come in handy,, Thanks..


Tony VVT

[Normster]

Norm
Do you mind posting this layout in a Visio.. Not for the amp but I see some very cool Macros that might come in handy,, Thanks..


Tony VVT

I don't think it's macros you're seeing here. Most likely the "transparent" feature in Visio 2003. Attached anyway.

[Fischerman]

IMHO putting a solid state clipping circuit in the amp completely defeats the purpose of building a tube amp in the first place...YMMV.

I see what you're saying dave but aren't we just trying to get the best tone? If so...then if by adding a SS clipping circuit we can make our tube amp sound better then we are serving our purpose and we should do it. I say give it a listen and tweek...put it in if it sounds better and leave it out if it doesn't...tube or no. But don't close your mind/options. Lots of folks get fantastic tones with SS clipping AND tube amps (any FF user...any Tubescreamer user...any Tube Driver user...any Silver Jubilee user, etc.). I really think the guitar amp world is missing out by for the most part 'segregating' tube and SS in guitar amps (aside from rectification and switching).

[talbany]

Norm

Thanks.. I just wanted to get the Power and standby switches.. Real Cool Looking!!! Thanks again...




Tony VVT

[Max]

IMHO putting a solid state clipping circuit in the amp completely defeats the purpose of building a tube amp in the first place...YMMV.

I see what you're saying dave but aren't we just trying to get the best tone? If so...then if by adding a SS clipping circuit we can make our tube amp sound better then we are serving our purpose and we should do it. I say give it a listen and tweek...put it in if it sounds better and leave it out if it doesn't...tube or no. But don't close your mind/options. Lots of folks get fantastic tones with SS clipping AND tube amps (any FF user...any Tubescreamer user...any Tube Driver user...any Silver Jubilee user, etc.). I really think the guitar amp world is missing out by for the most part 'segregating' tube and SS in guitar amps (aside from rectification and switching).

Friend of mine toured for years with an original Dumble ODS combo and the folks applauded to his great "Dumble Tone". Now the Dumble retired and he uses a 50Watt Music Man (SS in pre) combo (looks a bit similar from afar) and still gets the same applause for his great "Dumble Tone".

Cheers

Max

[FuzzFaceBuilder]

Hey all,
Just checking in for a progress report. I was looking at the Triad Dyna Clone OT's and was curious which was most likely used in 100w Dumbles? None of the OT's here have the normal 2K primary (EDIT: the A-451 has a 2.2K primary!) Would that be the one to go with for the project?

Also I have a heads up on a vintage Fender 1966 Showman Blackface AB763 Circuit 8 ohm Output Transformer. Is it really an 8Ω only OT from Fender? The serials are 022897 and 606646? The OT conversion # are 125A30A=022897. The Twin is 125A29A. Is the the only difference the secondary impedance?

Thanks again for everyone's help,
Hale

[JimiB]

I would recomend a marshall OT for what you are doing. Somthing like a marstran 100w OT would be really nice.