The Amp Garage

Excellent thanks for the ideas

I'll look at this at the weekend and report back.

The manual advises that for max overdrive, the boost channel volume control be turned up full, see p3 https://drtube.com/schematics/marshall/jcm800-sc-manual.pdf That makes sense, as it will result in V3a, the stage after the diode clipper, being overdriven. Additionally, I suggest that all the nor...

This is the correct schematic for 2205 i have been talking about. https://drtube.com/schematics/marshall/2205prem.gif Yep, that's the one I was looking at when I made my previous remarks But R16 looks to be a V2 cathode resistor, and V2 is exclusive to the normal channel signal path, rather than th...

This is the correct schematic for 2205 i have been talking about.

https://drtube.com/schematics/marshall/2205prem.gif

Yes its working as it should, my friend who owns the amp use's it on full gain, it does sound great but he would like a little more.

He rides the guitar volume, full on is for his solo's. We have tried boost pedals in front which does help but at the same time addes to the compression.

wow thats a great build, well done.

Can you point me in the direction of the schematic with your mods?

Cheers

Okay i'll give that a go, do you leave the diode in or remove it?

Cheers

Okay i'll give that a go, do you leave the diode in or remove it?

Cheers

perfect thanks

alkuz1961 wrote: ↑Tue Dec 06, 2016 7:28 pm ATTACHMENTS
PCB all.rar
(47.75 KiB) Downloaded 233 times

When I open the .rar file it comes out as a .Lay6 file, does anyone know what program I can use to open this?

I good friend of mine loves the boost overdrive channel on his 2205 He runs the gain on full but would like a little more overdrive. Looking at the schematic it uses a diode bridge for the clipping so not just a case of changing the gain on that stage. Anyone here had any experience getting any more...

Thanks for the info guys

The Rob Robinettes website is very investing reading.

Just wondering if anyone has the schematic for this amp yet?

It would be interesting to see what modifications Fender have done.

Thanks for all the advice with this.

The fault was due to two faulty zener diodes and one regular diode.

These all tested good in circuit with the component tester, even the zener's still had the knee in the trace.

All good now.

I have a hot rod Deluxe in for repair with a switching problem. This is not the usual one where it switches channels it self. With this the relays buzz when switched to OD, the output of the relay driver U3 is square wave hence the buzzing to the circuit is acting like a multivibrator. The power sup...