can you take a look at the amp issue thread i posted yesterday.

All right Myles, I've got one last question, and then I'll leave you alone, I swear

I am sending my amp (Fender Deluxe Reverb) in for service this coming weekend, and I wanted to make sure they did what I want, so I am going to leave them with some specifics. However, I have a vague idea about these items.

Firstly, I am going to have them do a quote, and diagnose the problem and let me know before they do anything. once the problem is identified, I will ask them to obviously fix it, but I will also ask them remove all of the tubes except for 2 (Tung-Sol 12Ax7's). I just put an order through for the following, and I think I will use the following complement (don't rule experimentation out):

V1: Tung-Sol 12AX7
V2: Groove Tubes 12AX7M
V3: NOS Mullard CV4024
V4: NOS RFT 12AX7
V5: Tung Sol 12AX7
V6: NOS RFT 12AX7

Power Tubes: NOS Brimar/STC 6V6GT (Matched Pair)
Rectifier: NOS GE 5AR4

Now my question is this, should I tell them to bias all of the tube pots, or should I not even bother to tell them. If yes, what should I tell them to bias the amp to if I want more of a Clapton blues/early 70's rock tone?

There is only 1 bias pot and the amp should be biased by your tech to a proper level.

For early Clapton blues tone this is not the amp to use. You would use a Marshall Bluesbreaker or Marshall JTM-45.

LOL, if I could afford one, or if it were prudent for me to do so I would. Don't get me wrong, I love my amp, and I'm replacing the tubes for the better. And also, the point of me doing this is also to reduce the role of the Fulltone OCD drive pedal I'm currently using. I basically want more amp drive, less pedal distortion. Although, it's safe to say I will still use it to some extent.

Anywho, I hear people talking about biasing the power section to a 5-6 rating or something like that . So should I just ask the guy to bias it to standard specs or something? or should I not bother at all?

Have the amp properly biased by a good tech.

Will do, however, while looking for resources about this, I came to your site with info. on the same amp under the personal setting tab, and became even more confused on the following section:

"...Tube compliment: Two Groove Tubes GT-7025's (in
V1 58/65 rating with a slow rise time for blues) and in (V2 85/92 rating for rock from the 60's), two GT 12AX7-C's (both with medium ratings), two
GT-12AT7's (one with a high fast rating of 116/120) and the MPI with a rating of 100/100) and one duet of GT-6V6R's with a #4 rating."

As I said before, what do I tell the repair guy? I know the preamp will bias itself, but regarding the one bias pot, do I tell him how I want the amp to sound, or will he only bias it if it is hindering the amp's functionality? I'm at an utter loss.

I know this is a major PITA, but I want this done right considering this is my first time, not to mention I don't know a lot about this, so I don't want to mess this up.

As always, thanks in advance
- Dan

Thank you so much, that is exactly what I needed to hear. And as far as that section I posted goes, i was only confused by the numbers.

Anyway, I got my order from Mike at KCA NOS Tubes (see previous posts), today, and I am probably putting those RFT's into V2 and V4 (pending experimentation) Also, the boxes the RFT 12AX7's came in had written numbers on their top. One had 105/101+ and the other had 106/110+. What do these mean?

Hello, Myles...

do you have any opinions regarding the sonic properties of KT66's vs. 6L6's and EL34's? Are KT66 in the same family as 6L6?

I have an amp that accepts both 6L6's and EL34's and was wondering: can you just put KT66's there and have it rebiased? Can I make generalizations in terms of what sonic differences I should expect? I currently have EL34's in the amp but was thinking of switching to 6L6's.

Hi Miles,

I'm new to the forum and Dr. Ellwood spoke highly of you as being the go-to man about changing one's tone/sound. In a nutshell, I have a JCM 2000 100 watt head w/ a JCM 900 cab. I use the stack with a Fender American Strat w/ a hot rails pickup on the bridge. In addition, I have a pod xt-live that I use for effects. I havent modified the head or cab in anyway. Lately, I've been displeased with the sound/tone of my rig (I feel that its a bit weak). I'm trying to get a tone that will sound like a mix of John Petrucci, Paul Gilbert, David Gilmour, and Stevie Ray Vaughn all in one (not sure if this is possible). Dr. Ellwood tells me that I should change some of the tubes on my head. He also suggested that I get a KLON CENTAUR which I am really considering. What are your suggestions?

Thanks.

Hi Myles,

Can you clear up a question for me? I'm looking to find out what wattage output a Fender "Pro Amp" is rated at.

Specifically, I'm interested in the brownface model 6G5, and model 6G5-A, and the blackface model AA763.

The Vintage Guitar Price Guide, as well as the Blue Book of Amplifiers, and the "Fender Amps; The First Fifty Years" book indicate that they are 25 watt amps. However the Fender Amp Field Guide says that the brownface Pro Amp is 40 watts.

http://www.ampwares.com/ffg/

Who's correct??

Hey Myles. Wondering if you could suggest a brand of NOS ECC83 I could source to use in V1 of a Cornell 18/20 Plexi combo? I have Sylvania Black Plates and various NOS examples but all prove too microphonic in V1 of that amp and caused problems. I have some current production GT ECC83 valves that are silent in V1 and causes no issues, but would still like to experiment with NOS flavours without the microphonics.

I have been recommended to look at short plate examples, having been told they are best suited to amps such as mine which are troublesome with microphonic preamp tubes. Can you confirm I might have better luck with these and maybe recommend one or two to look out for?

Many thanks and best wishes,

Tea.

Hi Myles.

Love your website, lots of great stuff !

I have a Marshall DSL 100 with a 1960B cabnet.I play a custom made guitar with 80's era Bill Lawrence L500 pickups in it.It plays and sounds incredible.

In my search for Sonic Nirvana and more power amp distortion at low volume, I replaced the stock Reflector plant Svetlana EL34's with Early Breakup "original" Svetlana (AKA SED) winged "C" El 34's. ( more bottom, smoother mids and highs but a tad less low mids/classic crunch)and I replaced the stock Marshall 12AX7 in V1 with a Tung Sol reissue, which I love.

These changes made a good amp great, but I'm still tweeking it,so.....

I still have stock 12AX7's in V2,V3,and V4.(Lots of life left in them and they don't sound half bad. I'm still trying to find out what they are !)

In my effort to get MORE EL34 distortion at lower volume, should I switch the V4 phase inverter to a high gain tube like the Tung Sol ? People recommend that you go with a Mullard 12AT7(4024), but it seems to me that using a lower gain tube would get you LESS EL34 distortion, adding compression and clean headroom that would break up the EL 34's later rather than early.( The opposite of what I want ) I like the way my rig responds to my playing touch ( I can add or subtract distortion by how hard I attack the strings )and I don't want to lose that.

Any thoughts on this ?

Thanks.
'Rocker

[quote=EastCoastRocker]
In my effort to get MORE EL34 distortion at lower volume, should I switch the V4 phase inverter to a high gain tube like the Tung Sol ? People recommend that you go with a Mullard 12AT7(4024), but it seems to me that using a lower gain tube would get you LESS EL34 distortion, adding compression and clean headroom that would break up the EL 34's later rather than early.( The opposite of what I want ) I like the way my rig responds to my playing touch ( I can add or subtract distortion by how hard I attack the strings )and I don't want to lose that.

Any thoughts on this ?

Thanks.
'Rocker

Myles,

Have you had the opportunity to play or hear the Rivera Venus 3? That amp should work better as a living room amp than my Quiana (which I love), right?

Thanks

>DO NOT use a 12AT7, this is the opposite way you want to go.

Thank you for confirming that to me. That's exactly what I thought, but I wanted to hear that from an expert.

>First off ... E34LS #2-3 biased at 72mA using the Marshall test point and procedure rather than their 90mA. You want MORE xover notch at lower output settings.

That was going to be my next question to you but you beat me to the punch ! Thanks, I'll try that. Will this yeild a similar result to removing two tubes and matching cabinet inpedience
to the two tubes ? How do you feel about removing the two output tubes on a DSL 100 ?

>Second and most important ... three of the preamp tubes are critical and one of those is the phase inverter. I use the http://www.groovetubes.com/SAG-MHG_Marshall_High_Gain_Kit_P1737.cfm in these amps.

I remeber seeing that on your website. I'm all for trying that out. What makes that phase inverter tube your choice ? I'm trying to learn more about the science of it all.

Thank you for taking the time out to help, you've been great.

'Rocker.

Hi Myles,

I talked to you at the Baked Potato Friday night during a break in Carl Verheyen's set (I'm the one moving to Florida).

Just wanted to thank you for going through Carl's rig for me...somebody else got to talking to you and I didn't get a chance to say Thanks. I really appreciate it (plus the heads up on the VHT power amps.)


Carl

Myles,

I believe the Venus 3 is switchable to 7 watts, compared to the 25 watt setting I currently use with my Quiana. Wouldn't that make a fairly big difference in volume?

Thanks,

Dave