Search through Pickmasters posts, he's got a mod that puts a pot in the FET input hole that controls the level of the PAB.

Not much help I know but you really need to take your amp AND cab to your tech and show him how to make the HT fuse blow. Then he'll be able to diagnose it.

As hiredhand said it could be a component on the board that got stressed by the Tranny blowing, but until your tech can replicate it reliably he's not got much to go on.

It is always engaged but when the pot is maxed the voltages are as designed, i.e full on.


No, because you are reducing the voltages to get your power reduction, tube life is not reduced and may even be extended. With a Hotplate you run your tubes at gigging levels but your speaker is producing bedroom levels. They are going to reach the end of their life sooner, but it won't kill them.

I had London Power http://www.londonpower.com/catalog/index.php?cPath=7&osCsid=fb65c5b33618800e48a4fc0537eee5eebudget kit installed for me by an authorised tech. Its not a simple fit, cathode bias amps need a small fan to cool the chips. It works by lowering the B+ voltage and the bias supply along with it. Tone is affected but I can get good tone at much lower volumes than my Hotplate.

I did mine a long while ago (and the FET) when I was building it. I used shielded cable and Nik does in the bluesmaster.  I used a small diameter pot Linear I think, but I really can't remember, same value as the trim pot. I used the spare holes in the back panel.

If you're competent with a soldering iron its a doddle. You'll need some heatshrink for the cable shield.

OK I'll have ago at answering some these , but you'll likely have to ask Nik or Mike(?) Klein.

1)  Serial, not switcheable unless you make your own. Passive ie no gain make-up what you lose is lost hence the need for the Klein or similar.
2) Don't know, sorry
3) I think the level depends somewhat on your input volume and ratio levels
4) Don't know, sorry
5) None this is a passive loop
6) Don't know, sorry

Personally I believe this amp is designed to be simple, after all it is 3 preamp valves and 2/4 poweramp valves. Compare this with my Fender Twin Amp which if my memory serves me well was 8+4. I had problems when I used my G# in the loop of the OTS on its own, it sucked tone badly. I then used a BBe Crossover to boost the signal prior to the G# and that improved it but I needed to be able to A/B and thats why I went with the Klein with footswitcheable hard bypass. It works well now. I strongly suggest you use a system that you can take out of circuit easily so you can be sure in your own mind its not messing with your tone. And it must be a true bypass, most of the TC stuff is not a true bypass as far as I know.

I think we can be sure that the combination of a Klein and any of the TC rack mount gear works well with the OTS, so why not go for this and get a really good Midi floor switch. There is no body of testing/opinion for other systems and if it was me and I was going your route I'd go for a Gigrig http://www.thegigrig.com/acatalog/FAQ_Amp_FX_Loop_Setup.html system. You could talk to them on the phone and I'm sure you'd get better service than from a big Corp like TC. I do believe you need to talk to someone who has actually tried a G-System in a PASSIVE loop and whose opinion on tone you can trust before shelling out for one.

No I haven't managed to find 5v4's yet, Hotrox haven't got any , but I'm in no hurry yet, love it just the way it is.

The Mullard EF86 is a very nice valve indeed, no problems with microphonics last evening and it does sound so warm compared to The JJ or EH. Will stick with it and get some more I think.

Before shelling out on a Powerbreak/Hotplate try one. My Hotplates work well with the OTS up to -8db  but with the DC-30 they are poor, thats one of the reasons I went for power scaling. I had it on about ¼ power last night and it was really nice. As I said before you do still lose something but its different to an attenuator where you lose tone badly.

Listening to Buddy Whittington today I love his tone, DrZ Maz 38 I think. I wonder how close the DC-30 is to that and indeed how different the 36wattTMB Ef86 is to the DC?. I'd love to hear one, seems to me that I naturally prefer EL84 amps.

Got to agree with that. I just need to know now which are the other hidden gems in Niks range? The OTS gets the most interest, but is it the best amp? well its horses for courses naturally, but I love the DC.


Work the guitar volume knob, this amp is all you need, something I'm not so good at ,  I've tried pedals aswell and still rely on a clean(ish) boost, but I think in time when I master the volume knob technique I'll probably lose most of them.

Cheers

Hywel Harris

Now in posession of NOS Mullard EF86. Installed it and its seems way better, I've just turned the volume up gradually and slowly and I can get it to MAX with NO squealing microphonic feedback. Previous valve I've tried you can't get past 12:00 and the one supplied by Nik was 10:45ish. These Mullards are still quite plentiful and because so few amps use them the cost is still reasonable, I paid less than the new price of the JJ EF806. I think I will keep the Mullard in reserve for gigs and use the JJ for normal use, and I will keep my eye open for another Mullard.

WIll let you know about the tone later, I'm taking it to rehearsal tonight, man are they going to complain about the volume!!!!!!!

I did. Thanks

Give it a good burn in. At least 24 hours, by all means play it but don't judge it until you have.

No I've not really used a pedal much, this amp is so repsonsive that I can get pretty much what I need from the guitar volume and channel swapping.

I know it is loud, but I need to know that if needs be I can turn it up without fear of uncontrollable squealing microphonics. I am bidding on a NOS Mullard EF86 after the advice from Mark at Hotrox, as soon as I get one I'll let you know.

I remember John Edmonds reporting here that he has now sold both his TR's sicne getting the OTS. Maybe drop him a PM

http://ceriatoneforum.com/index.php?action=profile;u=745

It sounds good, if anything a little less bright. Its still microphonic, you can still hear it in the background tinkling, but its much less prone to squealing than the EH, though as I said before it was a handpicked example.

I'm going to try modding the mountings of both the valve base and the chassis to see if I can reduce microphonic effects because at the moment its not really useable with the volume turned up loud, fine for most gigs but still, you need to know you can get a bit extra out of it if you need to.