Another old friend... Now a HRD > Bassman project!

[JSett]

Not such a convoluted story here. Just an amp coming back after an extended loan-out where it had been long enough they were selling it because they couldn't remember who it came from (and I'd changed my Facebook account) but I spotted it and recognised the name so fired him a text. They helpfully had it serviced regularly but I'll pull the cover tonight/tomorrow and check it all out. Looks like it's got some fresh Groove Tubes in the power section but I'll check later.

Standard issue MIM Hot Rod Deluxe but in some "limited edition" (lol) brown tolex and cloth. No idea of date, there's no writing on the tube chart and I can't find the QA sticker yet. Pretty sure it's a 2003 though.

Sound's as it should, which actually is always surprisingly good with these things. Yeah, they can break and the design in the chassis is gross, but they're pretty solid workhorses and are cheap on the used market - I think I only paid £200 for this originally.

It has acquired a burn from a joint on the top since I saw it last though



Welcome back

[JSett]

I had 10mins spare so took the back off at least:



Nice set of F&T's in the filter caps and the screen grid resistors have been changed. That's helpful and saves me a little money and time. I'll check the bias later but it sounds about right.

I'm tempted to gut and 5f6-a it. I've seen it done online and looks pretty easy.

[Dr Tony Balls]

1) is that the same cloth as on the head I built you? Certainly looks like it.

2)

I'm tempted to gut and 5f6-a it.

Like.....this?





More pics here: https://flic.kr/s/aHBqjzPZ25


Not a 5f6....more of a generic blackface (super, twin) but same idea. IIRC it was relatively straightforward. I used the existing iron as all of that is just fine. I designed a faceplate using the existing chassis holes and the knob config I wanted, so that was pretty simple. Mounted the board using at least one of the existing chassis standoffs. Probably the most (read: not very) challenging part was fitting sockets to the existing holes. Because the original sockets are board mounted the holes were a little larger than I was used to. For the power tubes I found existing sockets that were a good match for the holes. These. For the preamp tubes I wasnt able to find a good fit so I used some of these adapters and was able to get by. One could probably make their own too.

I wish more people would give me these things to gut and rebuild as its massively satisfying. All in all it turned out rad and achieved one of my favorite looks, the control panel with lots of dead space:

[JSett]

Like.....this?

YES!

I was thinking a 5F6-A or some AB763 derivative. Those links are very helpful actually as the sockets would have been the most annoying thing (I don't have chassis punches). I was hoping to do something where I can keep the reverb but hadn't got that far yet. Obviously my first thought was an AB165 combo though. The stock socket configuration is perfect really.

And yeah, that's replacement cloth. It looks identical to the one you used for me.

If you were on the same continent I'd send it to you for a conversion as I'm not sure my skillset in circuit design is good enough. Yet.

[Dr Tony Balls]

If you were on the same continent I'd send it to you for a conversion as I'm not sure my skillset in circuit design is good enough. Yet.

I'd be happy to do it, but you can do it too. Especially if you're sticking with something AB165 or the like. Reverb and Tremolo add extra variability and potential pitfalls to a build, but effect-less amps are a little more fool proof. Happy to help you or share my layouts or whatever. You've got it.

[JSett]

If you were on the same continent I'd send it to you for a conversion as I'm not sure my skillset in circuit design is good enough. Yet.

I'd be happy to do it, but you can do it too. Especially if you're sticking with something AB165 or the like. Reverb and Tremolo add extra variability and potential pitfalls to a build, but effect-less amps are a little more fool proof. Happy to help you or share my layouts or whatever. You've got it.

Hmm, no you've got my brain going.

Like, I can see a lot of things on yours that I understand. I can see where you've taken off the HT and filaments, the DIY centre tap (which I've had to do before), your preferred master volume type (which you remotely helped me install on my old Bassman), etc etc. My brain is getting a little better at reading schematics but translating them into the other dimension of an actual layout is where I fail. My head just can't seem to make the leap.

The only thing that jumped out at me on yours is no bias pot/points, so I'm guessing it's fixed?

I could live without reverb to be honest. I only use it at home and that's rarely too. If you still have a layout for the Ballsmom 50 then it'd be cool to have a look and see if I can make enough sense of it.

[Dr Tony Balls]

If you still have a layout for the Ballsmom 50 then it'd be cool to have a look and see if I can make enough sense of it.

I do, but it's not full and complete. It has a bunch of stuff that is omitted or wouldnt make sense to anyone but me. Lemme clean it up and i'll post it. Also if you want me to translate it to the form factor and transformers of the deluxe you have ill make you a new one with a proper schematic.

[JSett]

Also if you want me to translate it to the form factor and transformers of the deluxe you have ill make you a new one with a proper schematic.

I mean, that would be amazing

[Dr Tony Balls]

Aight this is basically what I used for the amp I built for you. Click through for a bigger version.



Notes:

1) This doesnt have any of the primary side stuff from the PT, only the secondary.
2) The big cap is a 40/20/20/20 uF cap can to save room but this could easily be discreet caps
3) The wires from point to point on the board I usually run underneath the board, but they dont need to be.
4) Any of the black circles are ground connections. I run all preamp grounds to the same connection to the chassis by the input jacks. Any other ground is generally run to a bolt on the PT, though some are run to more close and convenient places.
5) The master volume pot effectively replaces the two 220K bias resistors on the original schematic.
6) The bias supply is altered from the original....dont worry about that.
7) This doesnt have the secondaries from the OT, only the primaries.

And then let me know if you want to pursue an AB165 circuit in the deluxe (or anything else) and i'll happily work you up a proper schematic and layout for the build (though it will take me a few days to get the time).

[JSett]

Now, this looks thoroughly achievable for me. It's 100% reversed from how it would be laid out in a HRD chassis (and how I normally look at Fender layouts) but makes sense as it's logical that you do it that direction as thats how real schematics read. Obviously it doesn't have the heater leads and centre tap stuff but that's obvious to me with the work I have done on amps so far.

Also, it will cost not a lot at all in parts. At the worst maybe the equivalent of $200. The expensive parts are all there already.

I would very much be interested in a proper one, with discrete caps at the end of the line (seeing as there's so much room in the chassis and it's slightly less holes to drill). No rush at all, and you know I'll send over some 'beers' for your trouble - even though you'll say it's not necessary Obviously I'd just need the 1 channel version like you built me.

I can get 30 row turret boards ready made for about £20. Filter caps maybe £40, rest of the components including pots probably £100 at most if I go for Sprague, F&T, Alpha/CTS etc.

Also, if I do it, I might ask you to get a faceplate made for it as I have no source and I like yours. Without the BALLS branding obviously.

[Dr Tony Balls]

Yeah I tend to make my amps with input jacks on the left when you're looking at the control panel. Blame Dave Reeves.

And i'd happily get you a faceplate but I'd imagine there's a place in the UK that could do it easily for you. Do you have access to Illustrator or Affinity Design or something like that? I just send a file to a lady in Indiana who etches them and mails em to me. I think any old trophy shop or whatever would do.

[Dr Tony Balls]

OH....here's another thing. The HRD doesnt have a choke to work with. You can add one, or replace it with a resistor like a lot of amps do.

[JSett]

Yeah I tend to make my amps with input jacks on the left when you're looking at the control panel. Blame Dave Reeves.

And i'd happily get you a faceplate but I'd imagine there's a place in the UK that could do it easily for you. Do you have access to Illustrator or Affinity Design or something like that? I just send a file to a lady in Indiana who etches them and mails em to me. I think any old trophy shop or whatever would do.

Dave Reeves is my lead dress hero (as he should be for anyone working in amps).

I don't have access to any of that sort of software unfortunately. I'll have a look around though at possible sources. I only ask as you probably still have the correct file saved with all the dimensions. I'd keep the fender style jewel lamp though. One less thing to buy.

OH....here's another thing. The HRD doesnt have a choke to work with. You can add one, or replace it with a resistor like a lot of amps do.

Ahh, okay. I had a look and saw what I assumed was a choke, but now I realise that's a reverb transformer ! A resistor would be easier for sure

[JSett]

I do wonder if it would be worthwhile building it as a 6V6 pair, so it's a more sensible wattage. I guess that would just be some small changes to the power section supply to bias them correctly?

Not that there's a huge need with a MV but just spitballin'

[marqueemoon]

Aight this is basically what I used for the amp I built for you. Click through for a bigger version.



Notes:

1) This doesnt have any of the primary side stuff from the PT, only the secondary.
2) The big cap is a 40/20/20/20 uF cap can to save room but this could easily be discreet caps
3) The wires from point to point on the board I usually run underneath the board, but they dont need to be.
4) Any of the black circles are ground connections. I run all preamp grounds to the same connection to the chassis by the input jacks. Any other ground is generally run to a bolt on the PT, though some are run to more close and convenient places.
5) The master volume pot effectively replaces the two 220K bias resistors on the original schematic.
6) The bias supply is altered from the original....dont worry about that.
7) This doesnt have the secondaries from the OT, only the primaries.

And then let me know if you want to pursue an AB165 circuit in the deluxe (or anything else) and i'll happily work you up a proper schematic and layout for the build (though it will take me a few days to get the time).

I know dangerously little about amps, but it’s extremely cool and generous of you to share this info.