NAD!!!

[Toe-Knee]

As for re-biasing, I'm guessing I'd have to drop it into an amp specialist to get that done?

Depends on the amp and your own technical skills (and tooling). Some amps don't need biasing at all since the circuit takes care of it ("cathode-biased" aka "self-biased" amps like the Vox AC30 or Tweed Deluxe), some amps have a "bias point" (where you can get a reading of the bias voltage) and a trim-pot to adjust it so all you need is a multimeter, a screwdriver and a few advises from someone more knowledgeable, and finally a lot of amps don't have a bias point or trim-pot in which case, well, getting your amp to a real amp tech might indeed be the simplest (and safest) solution  :lol:

wrt/ your own amp it seems that it has a trim-pot but no bias point so if you have a good multimeter (one that can takes 400+VDC) and feel confortable working with lethal DC voltages here's a starter:

http://www.youtube.com/watch?v=V4T83PgEIhc

Also V1 = Clean and V2 = Crunch?

Here again it depends on the amp. In your case V1 is used for the first two gain stages (12Awhatever7 are double triodes - 2 gain stages in one bottle) so it's a very important part of your tone (everything else will reamplify what comes out of it) and it needs to be a very silent (no hum, no microphonics) tube.  V2 add some more gain and builds the preamp's distortion on what was provided by V1. Now it's not a channel switcher amp and both V1 and V2 are always on , so you can't really think in terms of "V1 clean / V2 crunch" (and FWIW even for simple channel switchers like the HRDx, Classic30 etc, V1 is still always on, you just have the option to switch V2 in and out of the circuit).

(disclaimer: overly simplified answer - I failed to find a decent schematic for the JCA20 and I'm not an amp tech).

To be honest if you do your research regarding your particular amp model and read some safety information biasing an amp is quicker and easier than changing strings on a guitar.

Well, at least there's no lethal DC voltage involved in changing strings  :lol:

That is a very good point! It's why i also mentioned to look up required safety info.

[dingleberry]

I am currently using a Bad Monkey

FWIW I used a bad monkey for a while, great pedal but definitely a bit of fizz added by the pedal when boosting a hi gain amp.  YMMV I upgraded to an OD808 and have never looked back.

Hard to appreciate the differences until you do a shootout in person I find.  If you want to stick with the digitech I'd be very conservative with the treble knob

[Nadz1lla]

Thanks for all the info, guys, really helps!

I can usually fix things myself, but when electricity is involved I feel a lot safer handing it over to an amp tech if possible. Just so happens we have a fairly good one in the area who Manson's send people to all the time. He serviced an old Marshall Valvestate I had once before I sold it, and when it came back to me it sounded so much better that I almost didn't sell it, heh. I had to in the end as we lived in a tiny flat and I had my Pod XT, so space took priority over the amp. >_<

I need to try me an OD808, heard a lot of good things. I got the Monkey because it was so cheap, but always open to other options.

[Toe-Knee]

Thanks for all the info, guys, really helps!

I can usually fix things myself, but when electricity is involved I feel a lot safer handing it over to an amp tech if possible. Just so happens we have a fairly good one in the area who Manson's send people to all the time. He serviced an old Marshall Valvestate I had once before I sold it, and when it came back to me it sounded so much better that I almost didn't sell it, heh. I had to in the end as we lived in a tiny flat and I had my Pod XT, so space took priority over the amp. >_<

I need to try me an OD808, heard a lot of good things. I got the Monkey because it was so cheap, but always open to other options.

I recently built an od808 and they really are perfect for metal. As is the od820

[dave_mc]

Dave - I am currently using a Bad Monkey, which I had researched a lot prior to buying. It seemed to come really close in most of the video comparisons I watched, and actually preferred the tone it gave over the "real" TS in one of the Tone King's vids. I do like what it adds to my tone, just the right amount of tweaking on the pedal side of things I think, heh.

ah right no worries, if you already have a BM it should be fine. Never tried one, but from what i hear it's more or less a tubescreamer with a bass knob. i'd swap speakers long before getting a "better" tubescreamer, but that's just me. i only tried the stock jet city speakers for a couple of minutes (as i already had the v12s and couldn't wait to get them in :lol: ) but they seemed a bit brighter/fizzier than the v12s. Granted breaking in should help that a lot, but even out of the box the v12s tamed the jet city down a good bit.

Well, at least there's no lethal DC voltage involved in changing strings  :lol:

you haven't seen me changing strings :oops:

[BigB]

I can usually fix things myself, but when electricity is involved I feel a lot safer handing it over to an amp tech if possible.

Well, it ain't rocket science neither and wrt/ high voltage it's just a matter of learning and applying the safety rules. To-knee's suggestion to google for more infos about biasing this particular amp is a good one, then you'll see if you feel you could do it or rather leave it to someone else.

wrt/ OD pedals, the BM is indeed Yet Another Variation on the ubiquitous Tube Screamer circuit, so if doesn't work for your amp and guitar you may want to first try another kind of  OD circuit. FWIW the TS doesn't really work for me on my amp's SLO-like channel (tried both my old TS9 and my homemade TS808), the Dano CTO1 (Cochran Timmy copy) is a way better match (not that this channel needs any more gain...).

Well, at least there's no lethal DC voltage involved in changing strings  :lol:

you haven't seen me changing strings :oops:

High tension has proved be lethal for guitar strings too, indeed :mrgreen:

[Nadz1lla]

Just watched that video.... yeah... I'll be giving that to someone else to do.  :?

I have a benign tremor which makes doing anything where you have to keep a steady hand very interesting, to say the least. I love to paint miniatures, but if you get a bad tremor, the worst case scenario is you have to re-paint that part. When an electrical current is concerned, I think it best to give that task to someone with a more reliable set of digits...  :lol:

[dave_mc]

High tension has proved be lethal for guitar strings too, indeed :mrgreen:

excellent :lol:

i've used the dano timmy copy too with my jet city and also the joyo ts copy. timmy is a lot more transparent, ts is middier. just depends on what you want. I tend to use the timmy as my always-on boost for rhythm tones and the ts for leads. but as you said, the jet city has a ton of preamp gain and it's not like it "needs" a boost.