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

[BoringPostcards]

I had that exact same amp in the same so-called limited edition colourway. It was a good amp, but I moved it on after a few years for no real reason.

[MattK]

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.

If you send me a sketch with dimensional specs I'd be happy to knock it out in Illustrator for you.

[JSett]

I had that exact same amp in the same so-called limited edition colourway. It was a good amp, but I moved it on after a few years for no real reason.

I honestly really rate the HRD amps. They were the defacto pedal platform 15+ years ago and were backline in almost every venue if provided. They have their (sometimes) major issues but a lot out there have already had the work done.

If you send me a sketch with dimensional specs I'd be happy to knock it out in Illustrator for you.

This would be fantastic! Thank you

[JSett]

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'm just pricing this all up. Angela want £36 to ship 3 of those adapters can't find any alternatives either.

So far, with going with F&T/Sprague caps, vishay resistors, switchcraft jacks etc, turret board, sockets etc it's looking at about £250 in parts to do the conversion.

[F15hface]

This thread has reminded me that an acquaintance has a blues jr ‘woody’ that’s broken which I’d love to put a tweed Princeton in.

Or a 6G2, but the internet has lead me to believe that’s a lot harder.

[JSett]

So I ordered a load/all the parts I'm likely to need. Just waiting on Tonys kind offer of a layout for the conversion (no rush).

I think I've managed to get it all for £220 (thanks MattK for finding some cheaper 9 pin adaptors). That's for everything except wire, which I already have tons of.

The only thing I'm ignoring for now is a faceplate.

[Dr Tony Balls]

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.

If you send me a sketch with dimensional specs I'd be happy to knock it out in Illustrator for you.

I have the file I used on mine which ought to be about the same, save for a different sized lamp hole.

[Dr Tony Balls]

I'm just pricing this all up. Angela want £36 to ship 3 of those adapters can't find any alternatives either.

Two alternatives: 1) I order them and send em t you for much less than 36 quid. 2) make something that does the trick.

Did you order a bias pot? If so which value and type?

[JSett]

I'm just pricing this all up. Angela want £36 to ship 3 of those adapters can't find any alternatives either.

Two alternatives: 1) I order them and send em t you for much less than 36 quid. 2) make something that does the trick.

Did you order a bias pot? If so which value and type?

MattK found some very similar ones on eBay from China for £11 for 4. Free postage (gonna be 3 weeks though, not that I'm in a hurry)



I did order a bias pot, I went with one of the 10k Linear CTS ones, seeing as it's a Fender circuit...



The filter caps I went with F&T in 47uF & 22uF flavours seeing as they don't do 40uF and 20uF exactly. Everything else was pretty much the right values. I've bound to have forgotten something though

[Dr Tony Balls]

Oh word, those look like they'll work just fine!

Cool, I wasnt sure if you were trying to do chassis mount or board mount on the bias pot. Also FWIW I find that unless i'm building the same amp twice I always have to adjust components in bias circuits to get a proper range of bias voltages. I'll set it up as it would be in a HRD but you may have to do some resistor swapping to get things to your liking.

What turret board did you get? Just wanna know the grid spacing for a layout.

[JSett]

Oh word, those look like they'll work just fine!

I'm going to drill a hole nearby to the bias part of the circuit and mount it like they did in the BF amps. Seemed logical to my brain seeing as it only has 1 fly lead and a ground connection via a 15k resistor.

Cool, I wasnt sure if you were trying to do chassis mount or board mount on the bias pot. Also FWIW I find that unless i'm building the same amp twice I always have to adjust components in bias circuits to get a proper range of bias voltages. I'll set it up as it would be in a HRD but you may have to do some resistor swapping to get things to your liking.

What turret board did you get? Just wanna know the grid spacing for a layout.

Yeah, I assumed some values might change when setting it up. I ordered a 100ohm 10w for the 'choke' replacement but I have others here already in similar sizes I can change out when it comes to it (the 100ohm was a guess based on other schematics out there)

The best turret board I found was a DR103 style one



At 45mm x 298mm x 3mm the biggest cap will be a squeeze but everything else should fit fine. Looking at your layout earlier, and allowing for a few caps at the end, I think the 30 rows will be enough. As long as the layout is right-to-left, my brain should be able to make any adaptations needed pretty easily

[Dr Tony Balls]

The best turret board I found was a DR103 style one

You have a link to the supplier?

[JSett]

You have a link to the supplier?

There's not exactly a wealth of information on it but options here in the UK seem limited.

I'm guessing there's about a 30mm gap between each row, which will mean there's some fancy leg bending going to happen with the filter caps

[JSett]

You have a link to the supplier?

I could order one of these instead if you think the space will be better?...

One from China

[Dr Tony Balls]

Hard to say. Those F&Ts are 38mm long, and the board you bought is 45 with the turrets set in a bit....it'll be a tight fit for sure but you may be able to elevate the caps above the turrets if there's not enough clearance.