OR15 Gain pot mod

[jamie_bkc]

Hi, so I've had the amp about a year now and I'm still dead happy with it. Although I find most of the time I have the gain between 9 and 10 o'clock, sometimes delving between 8 and 13. Beyond 2 o clock is more gain than I really use although it's nice to have.

Has anyone tried replacing the gain pot with a tapered one to make lower gain adjustments more forgiving?

[S&m freddy]

Hi

There is a nice thread here about preamp tubes that might be something that would work for you...and be easily reversible? http://forum.orangeamps.com/viewtopic.php?f=2&t=52870" onclick="window.open(this.href);return false;

[a.hun]

Hi jamie_bkc . Welcome to the forum!

Good suggestion that, good thread to read up on it.
(Handy those 'search function / favourites' thingies, eh? !)

Yeah I'd definitely try that before modifying the amp itself. The pot tapers that Orange use have always tended to be much more useful than on most amps anyway, doing useful stuff the whole way. Lots of people thought their big AD140s were 'too quiet' before hearing that you needed to turn the main volume controls right up to get the full power. With most amps (especially Marshalls IME) you'll get a lot of action at the beginning of the travel and from there things only get fuzzier, not louder.

I've always found the preamp controls on Oranges just as well sorted. However we all have different individual tastes and I think a bit of preamp valve swapping would help you find yours even better with your amp. Valve swapping isn't really a mod but it is a great way of tuning an amp to your own tastes, and preamp valves are both fairly cheap and long lasting.
You'll NEED to replace the power valves much more often, but preamp valves should normally last you for years. I'd say when you find ones you really like GET SPARES, run them for a couple of tens of hours to 'burn them in' (test for early failures) and you should be sorted for a good while.
(Assuming you plan to keep the amp that long, but why wouldn't you? They are great! )


Andy.

[jj_Bali]

Want a clean to mean tone in your Jim Root No4:

Regarding doing a mod to a Jim Root #4, I wanted a more controllable gain going from clean to nice rock-n-roll dirty and not having to rip parts of the board and spend a lot of time. I didn't buy this amp but took it in in a trade deal. So I tried a 12au7 in V1 and a 12ay7 in V2. It still has bite and chunky crunch hard rock - but I have available a clean tone if needed. And its easy to reverse.

clean = dial master volume to 3 - 5 o'clock , bring up gain as needed for output volume
Crunch = gain from midnight to 3 o'clock , bring up master volume as needed for output volume

If you find it doesn't have enough grit/massive attack - use a 12ay7 in V1.
Hope this helps !

JJ

[shedivines]

FWIW, Some guy on ebay sells cryogenized EH modern Ay7's that he claims sound better than NOS black plate 50's ones.