Nice playing,
Good old rock tone.

Hi Hywel,

You need overall lapped scree 4 core cabel ! fifth will be the earth.
get in Maplin http://www.maplin.co.uk/Module.aspx?ModuleNo=137

Hi Nick,
Nice to hear that.
D style preamp (RECKMOUNTABLE) with channel and boost switch, would be a great idea.
One can use it together with good rack processor and stereo tube power amp like VHT, Marshall, Mesa or CERIATONE 2-50w power amp (I’m dreaming) :.

Anyway small D amp is good idea as well, I already have couple of guys interested here in UK.

Mcinku ma man,

Some pics for you:

Boost gain pot inside and treble 47pF cap on vol pot.


and outside


OD trimmer and switch


filter caps


Internationall power reg. switch (left) and master pot cap selector (three way in half/full power hall)

Good thinking my friend!
Yes ! one can get variable trim-cap 250-1180pF, but I’m not sure about voltage though. Usually they are 100v max.  Made by Sprague-Goodman (US) and Murata (Japan).


Hi telecaster,

Yes you are correct! OTS 100 and 50 are identical and all mods apply to both of them.
100w already got 200mF filter caps so no change there.
Cheers

Hi Mcinku,

I have some pics and I'll try now, but soon I have to open my amp (again ) and I'll take more pics.

Be cool

Hello,

This is central scrutiniser again!
Some folks complained that removing the 0.05mF cap from V1’s NFB makes amp TOO FAT!  :
So here is more flexible solution – three way switch with 470pF/OFF/0.05mF.
Drill little hall for the switch near V1  and chose the desired setting.
I’ve added this to the layout.
Cheers.

You are absolutely right – in the middle OFF position a trimmer works, for other positions – the switch. One can put little trimmers instead of resistors to adjust desired gain settings on Hi gain and Plexi.
Well spotted Hywel, I’ve just corrected it! Caps cut highs – when gain increases highs increase too so to compensate!
One can chose caps value according to their taste.
Caps are connected to HOT not to shield (ground).

Hi Erwin,

I love sweet mud and dirt , well it does a little bit but 27K (one can put 12K as well) resistor opens up the tone and together it is magic (FOR MY TASTE)!.
Because of the bright 47pF cap on the volume is always ON - I’ve milded drive with 770pF - really Robben’s drive tone.
With experiments I've noticed that better to  keep V2A snabber low and increase V2B’s value – better chirp definition and waterier tone.

Sorry! Shame on me. I’ll correct it soon. It was there originally BTW, we have to tell Nick.

Hello tonelovers,

At last here are my tweaks on the OTS layout.
Those mods work for MY TASTE and not necessarily for other players taste and style.

WORNING !!! PLEASE DO NOT MESS WITH TUBE AMPS  if you don’t know how to. You can damage it or worse - IT CAN KILL YOU !!! Better take it to good amp technician !!!

I tried to make OTS bigger, fatter, bit more compressed, even on cleans. Actually get closer to “Bluesmaster” mod. Some of this tweaks can apply to HRM model too, especially removing a negative feedback NFB from V1 (just removing 0.05mF cap) which adds fat to the amp. Actually it would be better if one drills a hall near V1 and installs mini toggle switch for switching 0.05uF cap ON (for humbucker guitar) or OF(for strat and tele).
I hope everything is clear on the diagram.
Note that JAZZ/ROCK switch is three position switch and changes DRIVE CHANNEL gain only – Hi/Dumb/Plexi. Amp itself is always on ROCK setting.
BRIGHT switch is also 3 position for more flexibility.
As you noticed I removed FET board and there is boost gain pot in the FET input hall.
PAB is disconnected and gain boost happens with simply increasing a CLEAN VOLUME via PAB footswitch. With this you can have regulated (via boost pot) volume (gain) boost on both channels without changing the TONE. It allows to get nice crunch on clean channel and awesome drive boost.
Three way switch near V2 adjusts drive’s high cut, so you can go as smooth as you want without affecting clean channel.
Added International power switch (in the ground lift hall) for the travelling musician.

Best wishes to all

Hi Hywel

I hope this is very easy. Get 50k linear trimmer and hook it up to one side of the switch. Adjust mid scoopout with the trimmer while switch is on.



On this diagram PAB is disconnected. For my amp I’m using  more flexible boost system. I’m finishing my amps mod layout in couple of days and hope to publish it here.

Best wishes
Doc.

We (Mr. Woody, Peter Morris and yours truly) at the CCC sound lab, tested 10 different speakers in 10 identical 1x12 cabs and 10 position channel switching system.
All cabs were positioned parallely on the carpeted cement flore.
We've used my OTS on live gig settings and Patrick Eggle custom Strat with two singles and bridge humbucker. All speakers were worked out “non virgins”.

Test results:

1.   Celestion Gold (my & Peter’s favourite) big open sound, great lows, mids and crisp highs. Celestion G12-65 – Woody’s favourite – Robben’s tone!
2.   Tone Tubby alnico 12 – Woody’s fav – same as 65’s but bit brighter. Celestion Century – me and Peter’s fav – loudest, very fast and big open sound, very silverface  twin on cleans, bit harsher on overdrive.
3.   Celestion G12-classic lead 80 – big worm tone.
4.   Fane Alnico AXA12  100w – fantastic speaker but you have to play it loud to get magic out of it.
5.   Jensen 12 Neo 100 light weight – worm, loud, very Larry Carlton-ish tone.
6.   Eminence Cannabis Rex - Hemp Cones - very smooth with a monster tone.
7.   Celestion BL15 – 15’’ bass speaker – darker G12-65 but bigger mids and lows.
8.   EV M12L – 200 watt from my mesa boogie mark III – loud, almost PA clean, very middley, dry, nasty, dreadful speaker. Why people recommend it I have no idea. Much better to use EV 15’’ speaker – mild highs and great mid & low tone.
We also tried all speakers with Woody’s Two Rock, Bludo and Brown Note D’light 44 amps with the similar results.

Cheers

What you mean “There is nothing”
Oh! But their are more expensive then Two Rock or any other.
But sounds better though. 

www.customcabcom.com

check out design and products !!!

Bad idea !!!

Just keep JJs in all three position or Tung Sols.
If you put 12AT7WC in V3 - amp’s overall volume will go down.

Absolutely brilliant work!
Love the colour and 1X12 cab idea.