Help indentifying my mystery chassis

[bnwitt]

Ok, so as most of you have figured out I'm on an amp building frenzy here of late.  I have been pulling out all of my amp parts from my shop and putting together all of the amps I can because I want to get them out into the world or into my studio in case father time decides to put his hand on my shoulder.  With Tom Petty passing I'm even more driven.  Attached are some photos of a mystery chassis I bought quite some time ago and never did anything with that I am wondering which amp circuit will fit the best.  It is an original Fender chassis which has (4) octal sockets and (4) noval sockets.  It has two channels both with two inputs and a bright type switch.  Channel one has three controls and channel two has six controls.  Does anyone have any idea what this chassis had originally.  FYI, I know it's ugly but I will be giving it an Oxalic acid solution bath soon.

[pompeiisneaks]

Looks kinda like a bassman chassis to me, the later ones, silverface I think?  I'm no expert on the years/styles though :P

[shooter]

looks like a tetanus booster, or 58cents at the scrap yard

[bnwitt]

looks like a tetanus booster, or 58cents at the scrap yard

Never underestimate the power of Oxalic Acid.  I'll post a new picture after it gets it's 24 hour bath.  I'd take this chassis over most of the new ones made today which can't match the build quality.  Kind of like people.  Or at least that's what I told my bride when I was talking her into marrying me back in 94.

[bnwitt]

Looks kinda like a bassman chassis to me, the later ones, silverface I think?  I'm no expert on the years/styles though :P

That was my first thought.  I went through everything on the Fender Field Guide looking for the 4 and 4 tube configuration and the control layout but so far nothing.

[tubenit]

http://el34world.com/charts/Schematics/files/fender/Fender_Showman-AB763-layout.pdf

[bnwitt]

Dang Tubenit how did I miss that?.  I know I looked at the showman amps.  Ok then,  a Showman she will be again soon but with a 6G6 bias vary tremolo and a Hoffman board

[tubenit]

You could consider a 100w D-style amp with an onboard FX loop?   I'd think it'd be a reasonably roomy chassis for that?

Of course, a showman would be a great amp!

With respect, Tubenit

[bnwitt]

That sounds interesting.  Any links for one of those?

[pompeiisneaks]

You'd find most of the best information on that on the ampgarage.com site they have tons of dumble, trainwreck and other assorted build stuff going on over there. A bit different of an audience from here, but some of the same people (me, sluckey, tubenit etc).

~Phil

[tubenit]

http://ampgarage.com/forum/viewforum.php?f=5

There is considerable information about dumblish style FX on board with this ARCHIVES thread.

http://el34world.com/Forum/index.php?topic=10208.0

I've attached a schematic to show sort of the idea of what you could do.  I know you've done ALOT of Fender style amps, so perhaps this could be something different for you?   The ExpressSCH attached has the B+ rail and bias info

Maybe something worth thinking about?

With respect, Tubenit

[bnwitt]

Thanks Tubenit.  I'll take a look at that.  I happen to have a 100 Watt D style chassis, board/relay kit and head cabinet in the shop I bought way back when Allen was just starting to clone them over at The Amp Garage and when he was still sharing information about the layouts.  Then he clammed up and I never got around to building it.  100 watts is alot of amp for sure.  Maybe Nick over at Ceriatone has a layout I can use to finish this thing.  And by the way, I've done quite a few Marshall amps too not just Fender though it's true I am partial to Fender.  I know I am well over 100 amps under my belt by now and I must say things are a lot easier now then when I first started.  I've learned a lot in here and from Youtube's Uncle Doug, books by Merlin and others so my chops are much stronger  I am thinking about building a Sloclone this year too.  I went crazy back in the 90s and early 2000s buying amp parts and over the next year I intend to build my butt off using that stock.

[SILVERGUN]

There are plenty of layouts available over at amp garage
There are also plenty of options.
High plate vs low plate
Skyliner EQ vs classic...HRM vs non
You'll have to do some reading to figure out what fits the bill

[bnwitt]

I'll probably do a 183

[SILVERGUN]

Nice...you might have a hard time letting it go
http://ampgarage.com/forum/viewtopic.php?f=5&t=13095

[bnwitt]

Nice...you might have a hard time letting it go
http://ampgarage.com/forum/viewtopic.php?f=5&t=13095

I don't know, 100 watts is way too much for my studio work.  I've never played a Dumble amp so I'm curious.  Thanks for the link.

[tubenit]

I don't know if it is true or not ?, ..... but I've read numerous times that these 100 watt Dumble amps can get incredible overdrive at almost conversational levels because the overdrive is in the preamp and it has a rather stiff power amp.

It has seemed odd to me that this would be the case, but I've probably read a dozen different individuals making that claim stating that the amp doesn't need a power soak like Marshall's etc.  On TAG when guys start asking about either a 50w or 100w, the responses I see are often that you get the same overdrive at lower volumes on both amps.

My impression is this seems to be a different animal then most 100w amps.  I've heard Larry Carlton live several times and he did not seem loud to me at all.  In contrast, I heard Sonny Landreth play a Dumble and it was quite loud and "cranked" but that's more his style and intensity too.

With respect, Tubenit

[bnwitt]

Thanks Tubenit.  That's very interesting information.  I need to peruse that schematic to see the sense behind it.

[tubenit]

Check out this sound clip.  It is Da Geezer's amp which is a "102" style dumblish clone.  You can hear him talk and then play the amp with very little volume increase. In fact, you can hear some of his fret work. I think this was simply recorded by a cell phone, IIRC?  Besides being a great amp builder, he is an amazing guitarist.  He used to be a moderator here and was the guy who came up with the HoSo56, Tweed Overdrive Special and other designs. 

https://soundcloud.com/dageezer/twin-ultraphonix-test-1

It would be a great example of how you can get incredible overdrive at a conversational level as is claimed by many of the 100w cloners.  I think he used two 6V6's and two 6L6's in his at one point?

With respect, Tubenit

[bnwitt]

Thanks Tubenit.  I remember Da Geezer well.  Isn't he still around?  That sound clip sounds awesome.  He is quite the player and the amp sounds great.

[sluckey]

He changed his name to Geezer. Last logged on in May '17. Last post Sep '14.

[bnwitt]

He changed his name to Geezer. Last logged on in May '17. Last post Sep '14.

Good to hear.  When you get to our age you never know which friends are still around   Hey Geezer!  You still out there buddy?  I hope you're doing well.

[pompeiisneaks]

I don't know if it is true or not ?, ..... but I've read numerous times that these 100 watt Dumble amps can get incredible overdrive at almost conversational levels because the overdrive is in the preamp and it has a rather stiff power amp.

It has seemed odd to me that this would be the case, but I've probably read a dozen different individuals making that claim stating that the amp doesn't need a power soak like Marshall's etc.  On TAG when guys start asking about either a 50w or 100w, the responses I see are often that you get the same overdrive at lower volumes on both amps.

My impression is this seems to be a different animal then most 100w amps.  I've heard Larry Carlton live several times and he did not seem loud to me at all.  In contrast, I heard Sonny Landreth play a Dumble and it was quite loud and "cranked" but that's more his style and intensity too.

With respect, Tubenit

I also haven't had first hand experience but from looking at the schematics of the dumbles, I agree with this 100%.  They have a separate tube just for drive in the preamp, and the power and all sections are extra filtered, he seemed to go strong on filtering always to get cleaner power everywhere.  You can surely run the amp at much lower volume, and crank the drive up.  Also per a discussion I had with Jelle Welagen on facebook, (as well as others) the quad output tubes seem to create a different, better dynamic than just 2 in a push pull amp.  I think the points they made make sense.  (Jelle is one of the best dumble clone builders out there right now).

~Phil

[bnwitt]

Phil,
Is Allynmey still building clones?

[pompeiisneaks]

I don't think so, but may be mistaken.  He's no longer replying to my emails etc, to get a few fixes in place on ampgarage, so I suspect he's moved to other things at this point.  I did chat with him on the phone back when I first took over the admin and moderator of ampgarage, and he's been harder to reach ever since, he seemed to imply amp building has become less of a priority for him. I may have misunderstood, though.  As I recall, though he was the TW guru more than the Dumble one.

~Phil

[bnwitt]

You know you're right.  Allyn was the TR guy.  I worked with him to do the Asteroid amp layout with him providing photos and a schematic.

I'm thinking of Brandon aka Funkalicious groove.  He did the D chassis and board kits that I have.  I think his kit was based on an HRM 100 Bluesmaster.  I bought everything from him and then never got a layout.  Kind of killed the project.  It seems pretty close to Ceriatone's 183 version so I'm going to have to take what photos I have with that layout and try to make it work.

[pompeiisneaks]

There's a pretty good chance that would work for a lot of different dumbles.  I'd take a peek at others as well, That daughter board, I think is one of the mods (that goes on top of the main preamp board).

~Phil

[pompeiisneaks]

Does this thread seem like the right layout and info:

http://ampgarage.com/forum/viewtopic.php?f=5&t=12875

~Phil

[bnwitt]

Phil,
Yes that's the one I'm adjusting in Visio.  It's close but some of the board layouts are a little different especially the HRM board.  I'm sure I can figure out Brandon's variants.  Thanks

[bnwitt]

There's a pretty good chance that would work for a lot of different dumbles.  I'd take a peek at others as well, That daughter board, I think is one of the mods (that goes on top of the main preamp board).

~Phil

Yes that daughter board laying on the main board is the HRM board.  It's turned 90° from how it actually goes.