RK 50 MKII Bias observations

[sizzlingbadger]

First... this is not a post on how to bias your amp, we aren't allowed to post that here.

I have just re-tubed my Rockerverb 50 MKII and thought it would be interesting to some folks what the bias settings were like and what I ended up with. Those that re-bias can use the info and those that use amp techs can talk about it to them.

I took readings before changing and or adjusting anything and found the plate voltage was 390V and the original JJ EL34's were biased at 45mA which gives a static plate dissipation of 17.5W which is 70% of the EL34 max rating of 25W.

I swapped the power tubes for SED Winged C EL34's and then measured everything again without adjusting anything (its normally good practice to reduce the bias current with the old tubes in place before putting new ones but I wanted to see what the difference would be just for fun)

The plate voltage changed to 385V and the bias current had risen to 48mA which equates to 18.5 W thats getting on up to 75% (pretty hot) which shows why its important to get the amp re-biased when changing tubes.

I played the amp at several bias settings and settled on a setting of 40mA (393V) which is 15.7W or roughly 63%. This is a little cooler than Orange's factory settings so the tube life should be extended a little

The winged C's sound very nice too !

[jamison162]

I like my 6V6's bias around 60-65% max...18-20mA. They sound better cooler actually. Too hot and there's too much headroom, too hi-fi, kinda harsh and less compression. I like the warmer, rounder tone and sag/feel of running them a little lower.

[whiteyanderson]

My plate voltage on my MK II was a bit lower though at around 380. Mine came with Ruby's stock, biased at 38. I replaced them with JJ E34L and set them to 42 and there was a really nice improvement.

I'm no expert, but in my amp-head probe manual, it states that EL34 tubes should not be set to anything over 44. I found this confusing as my calculations led me to bias them at 46 if I wanted 70%. I was told by the guys at Eurotubes that the literature in the amp-head manual is incorrect. Sure do love that thing though with the PV switch.

Has anyone tried different power tubes yet? I have a pair of JJ 6L6's on the way and am looking forward to seeing if they get it to sound even closer to the MK I. I still think the MK I and II sound pretty identical, I just think the MK II has a little more rasp to it. It can be dialed out easily enough, but i'm wondering if a 6L6 will make it a bit closer. The MK I had just a touch more of a creamy tone to it naturally. Granted 6L6 is not the same as 6V6, I've never used a 6L6 but they seem to at least on paper share many of the same traits.

I've been wrong before though.

[a.hun]

I like my 6V6's bias around 60-65% max...18-20mA. They sound better cooler actually. Too hot and there's too much headroom, too hi-fi, kinda harsh and less compression. I like the warmer, rounder tone and sag/feel of running them a little lower.

Sorry, slightly OT but...



I like a cooler bias with most amps too, but for exactly the opposite reasons!

Within reason a cooler bias normally gives more headroom, clarity and less mushing up. And I know I'm not the only one who finds that...

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Different amps will respond differently to higher or lower bias, but generally if the amp is colder it'll sound more crisp but maybe more brittle, break up later but maybe feel too stiff, and sound more defined but maybe a bit flat. Hotter bias will generally sound more fluid but maybe a bit mushy, break up earlier but maybe feel too flubby, and feel more responsive but maybe a bit less defined.

Andy.

[jamison162]

I like a cooler bias with most amps too, but for exactly the opposite reasons!

Within reason a cooler bias normally gives more headroom, clarity and less mushing up. And I know I'm not the only one who finds thatAndy.

Not to argue but this does not sound to be the case to my ears or based on my experience. Feed the power tubes more current and there is less crossover distortion (or more headroom), less compression and a tighter more hi-fi sound and feel. Same princinple is being used with acoustic pickups and even effects pedals running at higher voltages like 12-18v....for more headroom.

Maybe I'm missing something but how does a tube drawing less current increase headroom?

[a.hun]

I like a cooler bias with most amps too, but for exactly the opposite reasons!

Within reason a cooler bias normally gives more headroom, clarity and less mushing up. And I know I'm not the only one who finds thatAndy.

Not to argue but this does not sound to be the case to my ears or based on my experience. Feed the power tubes more current and there is less crossover distortion (or more headroom), less compression and a tighter more hi-fi sound and feel. Same princinple is being used with acoustic pickups and even effects pedals running at higher voltages like 12-18v....for more headroom.

Maybe I'm missing something but how does a tube drawing less current increase headroom?

Well I said "within reason", meaning above the threshold of crossover distortion.

Put simply the reason that a valve drawing less plate current at idle has more headroom is that it has further to go before compression sets in = more headroom. A valve run hotter at idle has less room for an increase in current as the current is already higher. Compression will set in sooner. A valve running hotter at idle has less room to run hotter still when actually supplied with a signal to amplify. Literally less headroom.

I don't see it as being quite the same situation as effects pedals running at 18V versus 9V. There there is more headroom because the circuit can run at higher voltages so running at 18V is like having a bigger more powerful engine in a car. The capability of the whole system is simply greater than with a 9V system.
With valves the headroom is limited by any particular fitted valves themselves, and how you make use of that headroom is the defining factor to how much clean power you'll actually get before compression sets in.

Honestly with amps like for example my Hiwatt 100 or OR120 you'll get the most sustainable clean power out of them by biasing the amp as cool as possible. (Though naturally above the X-over distortion threshold). That means that when you make demands on the valves there is more room for them to be able to fulfil those demands. This is exactly how they were designed to be used and the standard stock bias was much cooler than seems to have become the fashion these days. With a hotter bias you have already used up some of the headroom before you even give the amp a signal to amplify. It'll run hotter at all power output settings and simply won't be able to sustain as high a clean output level as the power section will compress and distort quicker.

Counter intuitive or not a hot bias absolutely isn't the way to get the most power out of an amp. If you want the amp to saturate earlier and be more compressed at normal running levels than that is the way to go. People do have their own sonic preferences which is of course fair enough. But honestly that really is the way it actually works with most standard class AB amps.

Hot running types like Vox AC30 derivatives are different in that they don't sound that great until they are run relatively hot. But that is a different matter. There you are after the specific tonal qualities of these hot running (usually cathode biased) class AB amp designs and have to accept the trade off of lower power output ability. Anyway with cathode biased amps they will (for valves within normal performance limits) run very similar idling currents for different spec valve sets, so the amp is somewhat 'preset' to a hotter bias. If you want more power you use a different type of amp...

Covered all that in my "long post" on amp classes, biasing, power output etc. here:
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Remember a higher (negative) bias voltage = a cooler bias!
-36V bias on the grid will give a hotter bias than -46V bias. Is that maybe causing the confusion?

Andy.

[whiteyanderson]

Again, not a how to bias post. We are not allowed to post that here.

Interesting observations. I experimented with some 6L6's today in the MK II. I'll just copy and paste my findings on them at the bottom of my post. But here is where it gets interesting to me at least. This may not interest you guys at all. I'm no wunderkind with electrics, lets make that clear. I know enough to be comfortable and confident and SAFE to do basic, routine maintenance on my amps. And it helps me save some money. My father built and maintained communications equipment for the military and now does so for the US Post Office. He taught me how to do some things to be self reliant and most importantly, respect certain things that can end your life if you are not careful.

Anyway, upon installing the 6L6 and switching the tube selector switch to the 6L6/Kt88 side, I could not bias the tubes hot enough. Like barely got to the 1/2 way mark before I could no longer make an adjustment. In other words, I had maxed it out at 22ma vs the 44ma the 6L6 required. This of course, caused me a bit of concern so I went about doing some more research. I have not heard of too many of us taking advantage of the power tube swap. I did however find one other person who had, and he had the same issue.

He contacted Tech Support and was told that whichever side of the switch gets you in range, is fine. I also was told the same info. I dropped the 6L6's in today and everything was fine. They adjusted fine and there was plenty of room to go higher, on the EL34 side of the switch that is. I found it a little perplexing. As in if that's the case, then why HAVE the switch in the first place? But I'm OCD that way. And again, no electrical wunderkind.

So, sorry for a post of novel-eque proportions, just wanted to share that tidbit. And here are my observations on the 6L6 in the MK II. And the MK II in general after owning it for a few months now and going over it in almost every single way with a fine toothed comb. Of course, the obligatory YMMV .

At lower levels, they sounded nice and smooth, smoother than the EL34's, closer to the 6V6. However once I got the amp really open, say about 2 o:clock, the amp started to sound a bit "hollow". The magic was lost a bit. It was still definitely Orange, but not quite right. This was on the Dirty Channel. The clean channel, sounded much the same, slight subtle difference maybe.

I normally scoop my controls a bit, and the 6L6 is naturally scooped, it also had a bit of an effect on perceived volume, even when turning my mids up. It took about a notch and 1/2 more to open up into nice "power tube land" than the EL34's.

So, in conclusion, with 6L6GC's the amp sounds smoother, more like the MK I at LOWER volumes. When you crank it, it loses something. With EL34's, sort of the opposite. It sounds a just a tiny bit grainier, may even "midier" than the MK I when at lower volume. And as you turn it, up it just is a Rockerverb 50 as we know it.

My other conclusion is that the JJ 6V6's that I had in my MK I sound more like a 6L6 at lower volumes and more like an EL34 at higher volumes. I suppose this makes sense after my experience today. To me at least, or the way I dial in my amp. And also if you read Ade's comments on modern day 6V6 tubes he says "Nobody makes good 6V6's anymore, except for JJ and they don't sound like 6V6's anyway" or something to that effect.

My tube experimentation is done. However, I will say that replacing the stock Ruby EL34 tubes to JJ EL34 made it much nicer to me. I always used JJ's in my MK I, I just prefer them.

With all that said, after reading so much on it, and messing around and experimenting with it. I guess I just have to admit that the guys at Orange know what they're doing. I'm sure they realized the MK I was a dearly loved amp and when setting out to redesign it or, as they say, "improve it", they wanted to retain it's sound. Since there was what like 4 years give or take, between the MK I and MK II, I'm sure they took their time redesigining it to retain most of it's original qualities.

That's not to say that there is no benefit to being able to swap out tubes fairly easily. I'm sure for many people there are.

[a.hun]

...Anyway, upon installing the 6L6 and switching the tube selector switch to the 6L6/Kt88 side, I could not bias the tubes hot enough. Like barely got to the 1/2 way mark before I could no longer make an adjustment. In other words, I had maxed it out at 22ma vs the 44ma the 6L6 required. This of course, caused me a bit of concern so I went about doing some more research. I have not heard of too many of us taking advantage of the power tube swap. I did however find one other person who had, and he had the same issue.

He contacted Tech Support and was told that whichever side of the switch gets you in range, is fine. I also was told the same info. I dropped the 6L6's in today and everything was fine. They adjusted fine and there was plenty of room to go higher, on the EL34 side of the switch that is. I found it a little perplexing. As in if that's the case, then why HAVE the switch in the first place?

That's not to say that there is no benefit to being able to swap out tubes fairly easily. I'm sure for many people there are.
[/b]

I have to agree. I'm on record here saying that I find that bias range switch a totally pointless feature. It kind of gives the idea you can use different valve types easily, but in reality it is no different from any amp without that switch - the amps biasing will still need checked for a new set of power valves anyway. It certainly doesn't mean you can just switch ranges and the bias will be right. (Sounds like the exact opposite in your case in fact, it wasn't even in the right range! ) It also doesn't 'magically' let you use different valve types in an amp when you couldn't otherwise. A good tech could do that with a change of component value changes anyway for this type of amp.

I honestly think that for most users anyway changing power valve types is hardly worth the bother or expense. (Especially if you are including tech fees!) The sonic differences from preamp valve swapping are usually way more dramatic and that is also much cheaper and easier to do. Plus the fact that if you choose to use old stock preamp valves they will likely outlast your own use of the amp unless you literally keep it and use it regularly for several decades. Then you might have to replace them at some point. Otherwise with good guality old preamp valves you can practically fit and forget them.

I mean fair enough, if you know you really want the more defined top and bottom sound emphasis of a 6L6 set for your EL34 amp then no problem, get it adjusted to run them. But most amps are designed with a particular valve type in mind and the amp will probably work best (to most ears in most situations anyway) with that type. If you really want to experiment go out and get a THD Univalve or Bivalve or something similar which'll let you fit most power valve types without even having to worry about biasing and let you hear the differences. While I'd love to muck about with one of these THD amps I'm glad to say that I'm normally quite happy to find valves which work well in an amp and then leave them be until they need replaced. Guess I'm maybe just lucky that way and I kind of imagine having a burning desire to swap valves all the time as like having an itch you are just never ever going to be rid of. Sounds like torture to me.

Anyway, as far as the bias switch is concerned I reckon it is more an afterthought / a bit of subtle but effective marketing psychology, rather than a really useful feature. The high / low output damping factor switch always struck me as much more worthwhile on the RV amps which had it.


Andy.

[whiteyanderson]

I have to agree. I'm on record here saying that I find that bias range switch a totally pointless feature. It kind of gives the idea you can use different valve types easily, but in reality it is no different from any amp without that switch - the amps biasing will still need checked for a new set of power valves anyway. It certainly doesn't mean you can just switch ranges and the bias will be right. (Sounds like the exact opposite in your case in fact, it wasn't even in the right range! ) It also doesn't 'magically' let you use different valve types in an amp when you couldn't otherwise. A good tech could do that with a change of component value changes anyway for this type of amp.

I honestly think that for most users anyway changing power valve types is hardly worth the bother or expense. (Especially if you are including tech fees!) The sonic differences from preamp valve swapping are usually way more dramatic and that is also much cheaper and easier to do. Plus the fact that if you choose to use old stock preamp valves they will likely outlast your own use of the amp unless you literally keep it and use it regularly for several decades. Then you might have to replace them at some point. Otherwise with good guality old preamp valves you can practically fit and forget them.

I mean fair enough, if you know you really want the more defined top and bottom sound emphasis of a 6L6 set for your EL34 amp then no problem, get it adjusted to run them. But most amps are designed with a particular valve type in mind and the amp will probably work best (to most ears in most situations anyway) with that type. If you really want to experiment go out and get a THD Univalve or Bivalve or something similar which'll let you fit most power valve types without even having to worry about biasing and let you hear the differences. While I'd love to muck about with one of these THD amps I'm glad to say that I'm normally quite happy to find valves which work well in an amp and then leave them be until they need replaced. Guess I'm maybe just lucky that way and I kind of imagine having a burning desire to swap valves all the time as like having an itch you are just never ever going to be rid of. Sounds like torture to me.

Anyway, as far as the bias switch is concerned I reckon it is more an afterthought / a bit of subtle but effective marketing psychology, rather than a really useful feature. The high / low output damping factor switch always struck me as much more worthwhile on the RV amps which had it.


Andy.

Hey Andy,

I'm Andy too by the way .

I can see the convenience factor of having the switch, I mean you can swap out tubes that will fit within the tolerances without making any real modifications to the amp. Excuse my layman's terms in describing that, again, no wunderkind here, just know enough to save a few bucks and tweak around. I mean, I suppose the feature counts for something, as long as someone knows that you HAVE to have the necessary bias adjustments made to accommodate a given tube. Meaning you just can't slap in a pair of KT88 and rock out .

But yeah, if the feature is being advertised, I guess I expect it to work correctly. Meaning, if I flip it over to the 6L6 side, I should be able to bias it to it's correct range. I shouldn't HAVE to double check to make sure something isn't wrong with my amp. But, I'm anal that way, for XXXXX amount of money I expect this. It's not the end of the world though. I'm still and always be an ardent Orange man.

You're dead on about the torture thing and tube swapping though. The MK II as I have stated, sounds virtually identical to my old MK I, except for that little bit of grain and grit at lower volumes. I always loved that about the MK I. I could rehearse at home and not be too loud and it still sounded beautiful. I guess, that is the main gripe if there is one. But in hindsight, they surely must have changed something in it as it does sound like the MK I at loud volume. That leads me to believe that the pre amp much have been tweaked to accomodate the stock EL34's and the grit and grain is a byproduct of that tweak. I mean at bedroom volumes, you're barely, if at all getting ANY power tube saturation. So you're hearing almost all, if not all preamp distortion.

PS- to my ear, the MK II seems as if it has been set more to the LOW damper side of the MK I. It's definitely not the HIGH setting, thank goodness. Or maybe they found a good middle ground. You're right about that though. That was my BIGGEST worry about the MK II. I did not like the HIGH setting on the MK I at all.

I'm not sure if any of that makes sense, that's just my cockeyed view. And it took me awhile to realize this. Pretty obvious though I suppose . But it was causing me some torture. Why isn't it sounding JUST like like MK I at bedroom volume, yet sounds identical when I crank the volume...Duh. Sometimes the most obvious thing is the hardest to realize. So I went on a little tube swap fest.

I'm happy to be done with it though. I'm sticking with EL34's MK II. Excuse me if anything I have said is way off base. I've been on a little journey of discovery here.

PS- you are right about the damper. That was my BIGGEST concern about the MK II. It seems a if they've set it more to the LOW side though. Thank goodness, to my ear at least. I wasn't a fan of the HIGH setting. Or maybe they they found a nice middle ground. But it definitely leans more towards LOW than HIGH.

[whiteyanderson]

My final note on my observations. Sorry to the OP . I just figured why not lump it into the same thread.

After the 6L6 experiment, I put the JJ E34L's back in, this time I biased to JUST about 70% leaving a bit of leeway to accommodate for any PV swings. I had them a bit lower previously (around 65%) before I tried the 6L6. Anyhow, made a HUGE difference to my ear, remarkable actually. Pretty much all of the grit is gone now, indistinguishable from the MK I now in pretty much every way at pretty much every volume. I am chalking it up to the fact that JJ's must just like to be biased around 70%. I had the 6V6 JJ in my MK I at 70% as well. Anything below that, and they just don't shine as much. Of course this is subjective.

Final verdict: MK II kicks ass. If you are hearing a masssive difference between the MK I and MK II, it's either down to your tube choice and/or bias. Or you are retaining a magical memory of the MK I, and automatically being prejudicial towards the MK II. They are both equal and beautiful amps in every way. I love Orange.

I hope that somebody finds some of this helpful in the future.

[brian5258]

I just recently purchased a 50w MKII after having the opportunity to play through a friend's 50w MKI for well over a year. The MKII was the perfect amp for the sound I wanted - I was pretty disappointed when my MKII arrived and I plugged it up. I hear a lot of people on the forum say the MKII sounds just like the MKI, but I can't agree. Hopefully I just received some different tubes or bias settings and this is something I might be able to fix.

I'm not too happy with the MKII for a few reasons. There's a noticeable amount more of what I can only define as "harshness" in the high end.

I'm also not too happy with the low end. It's not that it doesn't have enough bass, it's more that the low end seems to break up, or "fart out." I'm more of a rock player, and my palm mutes just don't hold up anymore.

I tried swapping the Chinese "Golden Dragon" 12ax7s for JJ gold pins, but I didn't notice too much of a difference. Initially I figured swapping the EL34s for 6L6s would do the trick, but I was advised by an Orange tech not to do this as the MKII wouldn't have enough plate voltage to push the 6L6s properly. I was thinking about swapping the remaining preamp tubes (12at7s) with JJ gold pins as well but I don't want to waste the cash if it's not going to help with these issues. Do my issues lie more within the power amp tubes or the preamps?

I don't have the equipment to bias my amp myself but I'm willing to try anything at this point to get my MKII to sound like a MKI. Any suggestions will be greatly appreciated.

Edit: I have stock EL34s in currently. Will swiching to JJ EL34s make a difference in harshness/low end?

[jontheid]

I'm no expert, but in my amp-head probe manual, it states that EL34 tubes should not be set to anything over 44. I found this confusing as my calculations led me to bias them at 46 if I wanted 70%. I was told by the guys at Eurotubes that the literature in the amp-head manual is incorrect.

Eurotubes are right.

I cannot see any reason for not biasing EL34s to 44ma idle current if the amp has a plate voltage low enough such that this is still 70% or less of max plate dissipation.

My calculations give 44ma idle current if you are running at 70% with a plate voltage of 398V.

Svetlanana's 2002 EL34 datasheet rates the maximum DC cathode current at 150ma http://www.drtube.com/datasheets/el34-sed2002.pdf

I have no idea where this 'max 44ma for EL34s' nonsense comes from!

[whiteyanderson]

I just recently purchased a 50w MKII after having the opportunity to play through a friend's 50w MKI for well over a year. The MKII was the perfect amp for the sound I wanted - I was pretty disappointed when my MKII arrived and I plugged it up. I hear a lot of people on the forum say the MKII sounds just like the MKI, but I can't agree. Hopefully I just received some different tubes or bias settings and this is something I might be able to fix.

I'm not too happy with the MKII for a few reasons. There's a noticeable amount more of what I can only define as "harshness" in the high end.

I'm also not too happy with the low end. It's not that it doesn't have enough bass, it's more that the low end seems to break up, or "fart out." I'm more of a rock player, and my palm mutes just don't hold up anymore.

I tried swapping the Chinese "Golden Dragon" 12ax7s for JJ gold pins, but I didn't notice too much of a difference. Initially I figured swapping the EL34s for 6L6s would do the trick, but I was advised by an Orange tech not to do this as the MKII wouldn't have enough plate voltage to push the 6L6s properly. I was thinking about swapping the remaining preamp tubes (12at7s) with JJ gold pins as well but I don't want to waste the cash if it's not going to help with these issues. Do my issues lie more within the power amp tubes or the preamps?

I don't have the equipment to bias my amp myself but I'm willing to try anything at this point to get my MKII to sound like a MKI. Any suggestions will be greatly appreciated.

Edit: I have stock EL34s in currently. Will swiching to JJ EL34s make a difference in harshness/low end?

I don't know why they would tell you NOT to use 6L6, the amp is CLEARLY marketed to take 6L6. But save yourself the bother, they sound bad. I installed them and they worked just fine with a bias adjustment. Maybe they thought you meant 6V6 tubes? But if you want to try 6L6, take it into your tech and have him set it up.

As far as harshness. I had the same initial experience. How loud are you cranking the amp and what type of cabinet are you using? Is this the head or the combo? I have noticed that when the amp is cranked to a decent level (beyond bedroom levels) it's sounds virtually identical to the MK I. Also you need to tweak your EQ, if you set the EQ the way you remember you had it on a MK I, it doesn't sound the same.

If you are using an open backed cab, that may be another issue, I have both the MK I and MK II. My MK II is the combo version and it does lose a bit of it's grunt with the open back. Try it with a Orange PPC412 or PPC212.

As far as tubes, I did switch to JJ E34L's and it sounded much "smoother" even at lower volumes. Also I noticed that the stock tubes were biased really cold. I tried biasing the JJ's a bit colder and they still sounded a bit harsh. After biasing them right to 70%, they sounded "right".

Gold pins, to me are a waste of money.

Anyway, I think the keys are cranking the amp and you'll hear it sounds virutally identical. There IS a bit more grit to the MK II though, I assume because of the 34's. Also cab choice and making sure the bias is correct are important. If you have a combo try hooking it up to an external cabinet.

I can palm mute and do chuggas on the MK II and it sounds great. Of course once you've had the MK I or played one, there is also a mental hurdle to overcome. Even though I have both, if I had to choose, I would defend the MK I with my life. It just has some magical vibe to it.

[brian5258]

whiteyanderson,

Well it was more of a recommendation not to use the 6L6s, but since folks on the forum have tried them and haven't liked the sound, I'll stay away from them for now.

As far as volume, I notice the harshness pretty much throughout its range. It's definitely more noticeable at lower volumes, but since I don't have any volume limitations where I play/record, I pretty much keep it around 2-3 o clock. This is the head version of the amp, through a standard Marshall 4x12 @ 16 ohms. Granted, when I was playing through the MK1, I would use an Orange 4x12. However I played the MK1 through my Marshall cab a lot and never noticed what I'm hearing now.

Regarding EQ, it is quite different than the MK1 and I haven't quite nailed a "go to" setting yet. However, we use both of these amps in a studio environment, so using a ride range of EQ is typical and you pretty much couldn't make the MK1 sound bad with any reasonable settings. On both of these amps, I keep the treble pretty high, around 3 o clock, mids around 12, and bass around 1.

So my JJ EL34s arrived today as well as JJ 12at7s to replace the Golden Dragons I'm hoping they'll be the solution. I don't have any biasing equipment or electrical experience. I wish I could just throw the new EL34s in but I know you guys are going to tell me I need to get it biased :/

Without any measuring equipment, would it be a terrible idea to just bump the bias up slightly with the stock tubes just to see if it takes the tone in a good direction?

I plan to have the amp mic'd up during this process and would be happy to provide some comparison sound clips if anyone's interested.

[whiteyanderson]

whiteyanderson,

Well it was more of a recommendation not to use the 6L6s, but since folks on the forum have tried them and haven't liked the sound, I'll stay away from them for now.

As far as volume, I notice the harshness pretty much throughout its range. It's definitely more noticeable at lower volumes, but since I don't have any volume limitations where I play/record, I pretty much keep it around 2-3 o clock. This is the head version of the amp, through a standard Marshall 4x12 @ 16 ohms. Granted, when I was playing through the MK1, I would use an Orange 4x12. However I played the MK1 through my Marshall cab a lot and never noticed what I'm hearing now.

Regarding EQ, it is quite different than the MK1 and I haven't quite nailed a "go to" setting yet. However, we use both of these amps in a studio environment, so using a ride range of EQ is typical and you pretty much couldn't make the MK1 sound bad with any reasonable settings. On both of these amps, I keep the treble pretty high, around 3 o clock, mids around 12, and bass around 1.

So my JJ EL34s arrived today as well as JJ 12at7s to replace the Golden Dragons I'm hoping they'll be the solution. I don't have any biasing equipment or electrical experience. I wish I could just throw the new EL34s in but I know you guys are going to tell me I need to get it biased :/

Without any measuring equipment, would it be a terrible idea to just bump the bias up slightly with the stock tubes just to see if it takes the tone in a good direction?

I plan to have the amp mic'd up during this process and would be happy to provide some comparison sound clips if anyone's interested.

I'm going to PM you so we don't clutter the forum .