The Amp Garage

Yes, that'll do! Thanks all!

I just ordered a Dagnall 784-139 spec OT and C1999 choke. For the 1202-118 PT I'll be using the Tube-Town (Inmadout).

Only, now the UK is no longer part of the EU, that'll mean import taxes apply to UK transformers as well. Modulus by the way seem to offer reproductions of the late '70s/early '80s style transformers but not so much the late '60s JMP ones. For this build I'd like to get as close as possible in term ...

I'm thinking of having a friend build me a 50W Plexi (1968-1969 spec). The only question mark are the transformers. The European ones (modern Dagnall, TAD, Inmadout etc) don't seem as highly regarded as their American counterparts by Heyboer, Metropoulos, Marstran and Merren. Are there any worthy Eu...

It depends what you want to achieve with the amp. If you plan to use it at home only, a 10 inch speaker will suffice. If you are going to gig with it, and you have a loud band, you'd properly like an efficient 12 inch speaker. I generally like to use American Jensen-style speakers with Fenders thoug...

h4x0r wrote: ↑Tue Apr 14, 2020 11:55 pm What's with the prussian blue over everything? Tamper tell-tale? or QC?

The Harry Joyce website is down, but I'm pretty sure it's for QC, plus it tells whether someone else has tampered with the connections.

For those interested. In the end, we upped the resistor to 15K. The result was much more overdrive. Because there was a lack in low end, we decided to remove the resistor and capacitor all together. And the low end is all there now. Makes you wonder why Harry Joyce needed to cut low end, maybe becau...

Bumping this one.

Any thoughts on the value of the resistor on V2?

A kind fellow sent me pictures of his later HJ, including this one. What do you reckon? https://scontent-amt2-1.xx.fbcdn.net/v/t1.15752-9/s2048x2048/73082288_2195435167421310_8604253355834867712_n.jpg?_nc_cat=107&_nc_ohc=CbE8zv5RiEIAQk5BinG6ICrRm9rlggs0e6-ApUnLgovlez_lwlobgYe3Q&_nc_ht=scontent-amt2-...

A 1K5 resistor has the color codes brown-green-red-gold. You can find the same resistor on the V1 cathodes. Here are pictures of two HJ 50 watters. In both amps the said resistors have black dots on the brown stripe but to me it reads brown-green-red-gold. 15k would be brown-green- orange -gold. Wha...

Interesting... so my schematic might not be fully correct then? I based it on the two 50 watt models found on this website : https://hiwatt.org/ipage.php?n=13 This one as well: https://ampgarage.com/forum/viewtopic.php?p=40104&sid=9f140c3c87f22e130bba6138c7603215 I don't know really. But a 1k5 woul...

Interesting... so my schematic might not be fully correct then?

I based it on the two 50 watt models found on this website :
https://hiwatt.org/ipage.php?n=13

This one as well:
https://ampgarage.com/forum/viewtopic.p ... 38c7603215

On paper, that'd have like no gain and even less bass. Honestly, no reason not to run a trimmer there, and adjust the coupler to keep a similar bass cutoff to the original circuits. The OL amps had a pot labeled 'Overdrive' I believe 500k, but a 100k would probably be better suited to the Hiwatt vi...

You think so? Here’s an example, isn’t the resistor a 1K5?

https://hiwatt.org/pix.php?p=HJ50bGuts1

Here you go.

HJ just tweaked the early 80s lead circuit. it seems that the two 47nf coupling caps on 100w PIs were replaced with 4 22nf caps - one for each el34: "Although many people believe that these are the same, there are some major differences in sound and design. Besides the fact that Hiwatt amps underwe...