Anyone still have a layout/schem for the Bassman/Longhorn mods?

[hulakatt]

Does anyone still have a layout and schematic saved for the BillZ Longhorn mods to a Bassman? I used to have both saved but can't find them and it looks like Billy's site is gone. Haven't been able to find them with a quick google. search either. I think I still have a paper printout of the schematic but would like a copy of the layout before I start putting heat to solder.

Re: I have a '66 Bassman incoming that some fool stripped out and did a half assed kit build in.

[Chris Brown]

I have looked all over just out of curiosity, and no luck. Even archive.org is failing me here. I'm hoping someone here has it downloaded and can share it. Can you share that schematic?

[bcook]

Here you go.

[Chris Brown]

Here you go.

Thank you!!

[hulakatt]

Here you go.

Thank you! Jusy what I've been looking for!

[solderhead]

I have no other choice but to necrothread on this arcane topic. Here goes...

Here you go.

Thanks for posting that schem for the AB165 Longhorn mods. I've been looking for the Longhorn mods for the 6G6-B Bassman and so far I've come up empty handed.

As it turns out I have a Blonde Bassman coming in this week that is supposed to have (or have had) the Longhorn mods. I don't have the amp in hand yet so I'm not sure exactly what is coming. There is some confusion on the part of the person who is shipping it about whether the mods have been removed such that the amp has been restored to the original circuit with new parts, or whether it still has the Longhorn mods. I'm going to have to sort through this and a schematic of the 6G6 Longhorn mods would be helpful.

Is there a schematic available for the 6G6-B version of the Longhorn Bassman?

[Roe]

Is this the same Billy Zoom who was the tech of Brian Setzer?!

[solderhead]

Is this the same Billy Zoom who was the tech of Brian Setzer?!

I honestly don't know -- I'm doing research on this today and the information available is scant. To my knowledge he never used his full last name and just went by "BillyZ" which makes identification difficult. If you look hard enough, there are people who go by "BillyZ" with a variety of last names that begin with Z. It's not clear to me if the correct name might be Zoom, Zumwalt, or something else, or if he might hail from Texas, LA or the Pacific Northwest.

We have/had a member here who goes by the handle of BillyZ who might be the right person. I'm not sure about any of this, as he seems to have retired and now seems to be hard to find.

It's disappointing that someone else appears to have started using the name "Longhorn Amps" for a different business, which confuses the issue quite a bit.

It's not clear to me whether the amp I've got coming has his mods, is an original fender, or has been molested by someone since he worked on it. Because the amp bears his signature I'd like to make sure that the circuit is accurate to his specifications.

[didit]

Hello —

There are enough posts here on TAG covering the longhorn by member ‘billyz’ to reassure even a serious skeptic that he’s the originator. Has not posted for a few years but the profile suggests he still logs in from time to time. Try sending DM?

Billy Zoom is a guitarist known mostly the excellent ‘80s band X, out of LA. He does sessions and side gigs too. He also has a business in tube amp designs, perhaps most notably his own stage setup and the excellent little kahuna reverb+tremelo.

..

[solderhead]

Thanks to everyone who's posted.

At first I thought that our member @billyz was the right guy, but since his retirement he's been hard to find. It also looks like someone else has appropriated the name "Longhorn Amps" who I believe is not affiliated with him. Add to that the fact that there are multiple people who go by variants of the informal name of BillyZ in the music business who also design amps (ie: Ty Kendall/Billy Zoom) and this turns into a disambiguation problem.

I've read the Longhorn threads on the board, and I know about the user here named @billyz. I did try sending him a PM before necrotizing this thread, but I haven't received a response yet. So I thought I'd ask the members here for advice.

I understand that he is retired now. His web page billyz.net is gone from the internet, but it can be found on archive.org. I looked through the older pages from his years in Round Rock, TX and the newer pages following his move to Spokane, WA. His shop in Spokane is now closed. What strikes me as odd is that the longhorn schematic referenced above is conspicuously absent from all of the archive.org captures of his web site. The rest of the site is there, and his site is full of dead links to a non-existent longhorn schematic. It seems that the longhorn bassman mods that he shared openly while he was active here (by directing people to his web site to find them) are totally absent from the archived version of his web site. I don't know if that is accidental or purposeful, but it appears that the AB165 Longhorn Bassman schematic posted by @bcook is the only available Longhorn schematic online. Unfortunately I'm dealing with a 6G6-A Longhorn, not the AB165 Longhorn, so I'd like to find the right schematic.

I sent @billyz a photo of the amp with his autograph and work date written on the chassis, hoping that would encourage a reply. I'm hoping that he can get back to me to let me know what he would like me to do. The problem is that I've got an amp on the bench that has his autograph on the cabinet floor, on the doghouse and inside of the chassis near the PT. He was obviously proud of his mod as he signed the amp 3 times on one service visit -- buy the amp no longer appears to have his mods. Examination of the circuit shows that somebody appears to have ripped out his work and returned the amp (mostly) to stock, but left his signature in place. It looks like a dufus got hold of the amp when it was "restored" to original specs, and really botched some of the work. It's going to need some serious attention to make it electrically-safe.

The Blonde amp was sent to me with the claim that the mods had been removed and the circuit was restored to the original 6G6-A schematic. That claim isn't accurate. In it's current state the amp has not been fully restored to the original circuit, nor does it contain the Longhorn mods that are referenced by his signature. It's in an intermediate fucked-up state that indicates that it was last serviced by an idiot who was so sloppy in his work on the bias circuit that he melted through most of the wires on the PT -- there are red HT wires that are melted so badly that the bare copper HT wires are exposed. If I were him, I would not want my signature on this amp. I'm going to fix all of the problems, which are going to require removing the PT and replacing several leads as well as revising some truly abhorrent wiring, replacing resistors that don't match either the Longhorn or the 6G6-A schematics, fixing lead dress problems, etc.

I'd like to ask him if he's still willing to share the schematic, and if he cares whether the amp continues to have his signature on it after his work has been removed. I'd be willing to restore it to his specs if he can provide them, and I'd be willing to remove his signatures if he no longer wants them on an amp that somebody else screwed up after he had signed it. I know that I wouldn't want my signature to remain on this amp after somebody else got hold of it and screwed it up this badly.

[didit]

BillyZ has shared his phone number many times over the years -- +1.512.590.9234. Suggest you try calling and encourage him to perhaps post those schematics here on TAG for posterity.

..

[solderhead]

Thanks for helping. Is that a current number? It looks like an Austin, TX area code and I understand that he had relocated to Spokane, WA. I guess it could be current if he took his cell phone with him and kept the Austin number when he moved.

Regarding the schematic -- I don't know that I really need a schematic for this amp that I've got on the bench, but I'd like to have it to verify what I'm thinking. Looking at the available schematic posted above, the Longhorn mod for the bass channel appears to have taken the TW Express' 3 gain stages and utilized the leftover triode by converting the input stage to run as parallel triodes, like you'd find in a Matchless. The mod circuit should look familiar to anyone familiar with the Express.

Interestingly, there's a billyz from Spokane who is still active at audiokarma.org:
https://audiokarma.org/forums/index.php ... t-activity

[Mark]

Here you go.

That seems like the normal Fender circuit. Really didn’t see any difference. If I have missed something please point it out.

I believe Miles built/modded an amp that was along the lines of the Longhorn mods. I can’t remember if it was based on Trainwreck, I suspect it was a Dumble circuit.

[didit]

Hello --

Thanks for helping. Is that a current number?

Perhaps take 30 seconds and try dialing him, and discover it could be? As aside, board logging for BillyZ shows him still active here in early January.

Here you go.

That seems like the normal Fender circuit. Really didn’t see any difference. If I have missed something please point it out.

Look closely you'll see there are various small but significant mods. One key example: the 3rd stage triode cathode resistor is 10K -- similar to a Trainwreck.

Best ..

[billyz]

I am Sorry I never saw this thread. Yes, I am retired and living in Spokane,Wa. I do still work on interesting and vintage amplifiers from time to time. I do a far amount of work for a local backline company as well.

I have not done a Longhorn Bassman mod in quite a while. I did do the mod to both the 6g6a and Ab165 bassman. Probably to other Bassman circuits as well. One thing I remember is problems with parasitic oscillations and or Blocking distortion. Sometimes I added a grid stopper to the subsequent preamp stages, usually 1.5k . Shielded cable is probably necessary. And I found there is one under board link wire that seems to be particularly offensive, see pics 6599 and 6600. Moving it to the top of the board improves the problem. I do not remember all the nuances I discovered about the Bassman mods I did.

I have done crazy mods to Showmans, Twins, Tweeds , many Marshalls etc. I usually signed my work unless I was fixing someone else's botched job.

Here are some pics and notes and schematics ( edited from the originals) . Hope this helps.
And yes, This was all inspired or stolen from the Trainwreck Express .

I cannot add anymore files or attachments.

By the way this amp is loud and probably needs an Attenuator or master volume ( Ken Fischer type 2 is a favorite of mine) I did speak to Ken a few times to help me out with some crazy Ideas I have tried. He was always Spot on.

I am BillyZ or Billy Z , not Billy Zoom. Very early on many people started calling me Dr Z. Then One day I saw a reference to a Dr. Z in a Vintage guitar mag . So I called him and we had a good chuckle when he told me he knew of several Dr. Z's. After that I made an effort to have people refer to me as Billy Z. The Z is for Zumwalt. Everyone was butchering it , so I told them just Billy Z.