Feel free to ask Myles

[nphase]

well, it sounds phenomenal, you only hear the buzz when you're not playing anything

[sgguitarzz]

Myles -

 

I just picked up a Rivera R55. It has 2 Svetlana EL34's and 5 crappy Sovteks. I believe the Svetlanas were recently put in but I am sure I can do better than the Sovteks for V1-V5. Here is the layout:

 

V1 Input buffer and tone control driver for Channel 2, and also the first preamp stage of Channel 1

 

V2 Tone control follower for Channel 2 and an additional gain stage for Channel 1

 

V3 Final stages for both channels before the mixer stage

 

V4 Reverb follower and the mixer stage, provides gain to the reverb pan

 

V5 Phase inverter driver tube for the power amp section

 

Any recommendations? I play a wide variety of music from classic rock, blues to oldies and a little harder stuff here and there. I need a good clean, nice reverb and good OD/distortion and that is why I bought this amp because I have heard it can do all that. Thanks in advance for your help.

 

[Dr. Ellwood]

Hi Miles, I'm trying to figure which tube is the V2? from left to right from the back of the amp it's, 5881,5881,7025,7025,12AX7,12AX7,7025,7025....this is a Pro Model 6G5

[myles_rose]

Myles -

 

I just picked up a Rivera R55. It has 2 Svetlana EL34's and 5 crappy Sovteks. I believe the Svetlanas were recently put in but I am sure I can do better than the Sovteks for V1-V5. Here is the layout:

 

V1 Input buffer and tone control driver for Channel 2, and also the first preamp stage of Channel 1

 

V2 Tone control follower for Channel 2 and an additional gain stage for Channel 1

 

V3 Final stages for both channels before the mixer stage

 

V4 Reverb follower and the mixer stage, provides gain to the reverb pan

 

V5 Phase inverter driver tube for the power amp section

 

Any recommendations? I play a wide variety of music from classic rock, blues to oldies and a little harder stuff here and there. I need a good clean, nice reverb and good OD/distortion and that is why I bought this amp because I have heard it can do all that. Thanks in advance for your help.

 

On the Svetlanas .... which Svets? There are two different ones ... ones from New Sensor (Sovtek) marked as Svetlana or SED, and there are real Svetlanas with a winged C logo. They are very different and from two completely different companies from two different plants in to very distant geographical locations.

 

What is the bias set at?

 

Do we know if the tubes are low, medium, or high in the range of an EL34?

 

On the preamp tubes .... this is really personal taste. The Sovteks could be great. There are many Sovtek tubes. The 12AX7LPS is a great tube in some places such as the phase inverter and to give more girth when used in a first gain stage.

 

I need to know what is in V1, V2, and the phase inverter position.

 

 

[myles_rose]

Hi Miles, I'm trying to figure which tube is the V2? from left to right from the back of the amp it's, 5881,5881,7025,7025,12AX7,12AX7,7025,7025....this is a Pro Model 6G5-A.

 

V1 is the preamp tube most close to the input jack and the farthest from the output tubes. You count from V1 .... V2 is next to V1.

 

 

[sgguitarzz]

The Svet EL34's are not the new SED Winged C's. They are the old type. All the Sovteks are 7025/12AX7WA. I couldn't tell you the bias as I am not that knowledgeable in that area.

[myles_rose]

The Svet EL34's are not the new SED Winged C's. They are the old type. All the Sovteks are 7025/12AX7WA. I couldn't tell you the bias as I am not that knowledgeable in that area.

 

For a start get rid of the WA's in V1 and V2. You can replace them with almost anything. They are dark, compressed and the lowest gain of any of the 12AX7/ECC83/7025 family.

 

My personal preference for V1 and V2 in this amp for great overall use is a 12AX7R2 in V1 and 12AX7R3 in V2. If you want more of a British flair then in V1 use an ECC83S.

 

If you want a hard rockin' monster then use the SAG-MHG kit that has two very high gain (selected and traced) ECC83S tubes for V1 and V2 and a SAG-AX7-MPI matched phase inverter that is currently made from the 12AX7M GT Mullard reissue.

 

Since we do not know when the output tubes were replaced and don't know if the bias is right have that checked and make sure it is around 38mA.

 

You may want to replace the output set as they tubes you currently have are some of the thinnest sounding EL34 tubes out there. In the Rivera amps I now use the EL34M or EL34R2 (winged C Svets) in a #6-7 rating biased at 38mA.

 

 

 

 

[sgguitarzz]

Thanks for your advice. Much appreciated. I just tried it out and while it really sounds good I imagine with better tubes it will be at another level.

[Zwol]

Hey there and thanks in advance:)

 

I am wanting to re-tube a Traynor YCV 40wr stocked with Sovteks......I like the amp and speaker...but the overall sound is not so dynamic. I am running into a Weber Mass Lite into a power amp and then to the Celestion Vintage 30 so i can crank the tubes at lower volumes but still canna get the dynamics and harmonics i know the Amp is capable of. I have read over many other suggestions on Harmony Central,

I have seen so many diff scenarios (see below) that i am filled with Question.

I am looking to make the Clean channel break up less early then it does which is at about 5...i want to be able to have a louder clean sound before it breaks up...which would be ideal anywhere after 6 or so.

As for the gain Channel it is so bland!!!! I want more dynamics and a less muddy more creamy sound.. from the channel.

I read on Harmony Central that the Bass, Treble and Mid controls actualy work wonders when the amp is re tubed:)

ANY suggestions at all would be apprieciated!!! Cost is not to much of an issue, the amps sound is more impt.

 

J

 

 

Tube examples i've read of...not tried.

----------------------------------------

Replaced all of the tubes in the amp, going for a NOS Mullard 12AX7 in V1, and NOS GE 12AX7 in V2, a balanced JJ ECC82S in V3, and two JJ 6L6GC's in V4 and V5. I also have a Weber MiniMass attenuator between the output tranny and the speaker.

--

Electro Harmonix 12ax7EH preamp tubes and a matched pair of SED Winged C 6l6gc power tubes

--------

v1/v2 - TungSol 12ax7 (re-issue)

v3 - JJ ECC83-S (balanced)

power - JJ 6l6GC (matched)

----

2x SED 6L6, 2x JJ12ax7 and 1x tt12ax7

-----------

3-JJ ECC 83 S

2-Schuang TAD 6L6 GC Tall Bottle

[myles_rose]

Hey there and thanks in advance:)

 

I am wanting to re-tube a Traynor YCV 40wr stocked with Sovteks......I like the amp and speaker...but the overall sound is not so dynamic. I am running into a Weber Mass Lite into a power amp and then to the Celestion Vintage 30 so i can crank the tubes at lower volumes but still canna get the dynamics and harmonics i know the Amp is capable of. I have read over many other suggestions on Harmony Central and am also in light contact with Lord Valve who suggested......

 

3-JJ ECC 83 S

2-Schuang TAD 6L6 GC Tall Bottle

 

I have seen so many diff scenarios (see below) since his suggestion that i am filled with Question.

I am looking to make the Clean channel break up less early then it does which is at about 5...i want to be able to have a louder clean sound before it breaks up...which would be ideal anywhere after 6 or so.

As for the gain Channel it is so bland!!!! I want more dynamics and a less muddy more creamy sound.. from the channel.

I read on Harmony Central that the Bass, Treble and Mid controls actualy work wonders when the amp is re tubed:)

ANY suggestions at all would be apprieciated!!! Cost is not to much of an issue, the amps sound is more impt.

 

Jason M

jznoir@yahoo.com

 

Tube examples

----------------------------------------

Pretty simple set-up at the moment, but it suits me just fine. A quick note before I get into the awesome sounds this thing is capable of...I have replaced all of the tubes in the amp, going for a NOS Mullard 12AX7 in V1, and NOS GE 12AX7 in V2, a balanced JJ ECC82S in V3, and two JJ 6L6GC's in V4 and V5. I also have a Weber MiniMass attenuator between the output tranny and the speaker.

--

I loaded mine with Electro Harmonix 12ax7EH preamp tubes and a matched pair of SED Winged C 6l6gc power tubes

--------

v1/v2 - TungSol 12ax7 (re-issue)

v3 - JJ ECC83-S (balanced)

power - JJ 6l6GC (matched)

----

2x SED 6L6, 2x JJ12ax7 and 1x tt12ax7

 

 

This is really a personal taste issue and it looks like you have experimented across the range a bit already. I find the Tung Sol Reissues a bit thin in this amp in V1 ... I prefer the 12AX7R2 (a Sovtek 12AX7LPS) but that is my personal taste. I prefer the R2 over the M as the M is a bit dark.

 

On output tubes I like the GT-6L6GE in a #5-6 rating biased at 32mA. Bias too high and the amp is harsh. Too low it is grainy.

 

 

[Dr. Ellwood]

Hi Miles, I'm trying to figure which tube is the V2? from left to right from the back of the amp it's, 5881,5881,7025,7025,12AX7,12AX7,7025,7025....this is a Pro Model 6G5-A.

 

V1 is the preamp tube most close to the input jack and the farthest from the output tubes. You count from V1 .... V2 is next to V1.

 

 

HI again Myles, well I tried a new 7025 in the V2 position and it's still at half volume on the tremlo channel, what's next? should I pull all the preamp tubes out and replace them? (I mean on the trem channel only) the regular channel is perfect? thanks ..LEE, I just am trying to avoid taking this amp back into Bruce Egnater, it takes too long to get back, but I will if I have too.

[myles_rose]

Hi Miles, I'm trying to figure which tube is the V2? from left to right from the back of the amp it's, 5881,5881,7025,7025,12AX7,12AX7,7025,7025....this is a Pro Model 6G5-A.

 

V1 is the preamp tube most close to the input jack and the farthest from the output tubes. You count from V1 .... V2 is next to V1.

 

 

HI again Myles, well I tried a new 7025 in the V2 position and it's still at half volume on the tremlo channel, what's next? should I pull all the preamp tubes out and replace them? (I mean on the trem channel only) the regular channel is perfect? thanks ..LEE, I just am trying to avoid taking this amp back into Bruce Egnater, it takes too long to get back, but I will if I have too.

 

Replace the preamp tubes one at a time.

 

If it is not a tube then it is time for the amp to see a techs bench.

 

 

[Dr. Ellwood]

Myles would the vibrato oscillator,7025 @V3, cause the same symptom? because I notice the vibrato does not work as well as the volume being at half volume?

[myles_rose]

Myles would the vibrato oscillator,7025 @V3, cause the same symptom? because I notice the vibrato does not work as well as the volume being at half volume?

 

Like I said before .... swap out the AX7 types one at a time.

 

Half the vibrato tube is a recovery stage from the gain stage and tone stack loss.

 

You will learn more much faster and figure out things about the amp if you do what I said earlier.

 

 

[Dr. Ellwood]

Ok thanks Myles, yeah I sure will do that, at least I know I have one good tube to swap around between the suspect postitions to see what happens!

[blueross]

Hi Myles,

 

Newbie here... I have a Rivera Fifty Five Twelve and I get some rattling when I'm on a moderate volume and certain chords/low end frequencies, usually a first position G. I've tried to sit behind the amp while it is happening, but I can't find anything loose or any other sign of the source of the noise. Nothing is coming through the speaker, so on high volume it isn't noticeable, but it's annoying at moderate to low volumes.

 

What should I be looking at? Tubes?

[myles_rose]

Hi Myles,

 

Newbie here... I have a Rivera Fifty Five Twelve and I get some rattling when I'm on a moderate volume and certain chords/low end frequencies, usually a first position G. I've tried to sit behind the amp while it is happening, but I can't find anything loose or any other sign of the source of the noise. Nothing is coming through the speaker, so on high volume it isn't noticeable, but it's annoying at moderate to low volumes.

 

What should I be looking at? Tubes?

 

it is probably a microphonic tube

[blueross]

If I start replacing like for like, do I need to worry about rebiasing (which I'm not equipped to do).

 

Thanks,

[myles_rose]

If I start replacing like for like, do I need to worry about rebiasing (which I'm not equipped to do).

 

Thanks,

 

If you have the same GT tube at the same GT rating you do not have to rebias if it was done properly the first time.

 

If the output tubes are non-GT then you do have to rebias.

 

 

[Dr. Ellwood]

Ok thanks Myles, yeah I sure will do that, at least I know I have one good tube to swap around between the suspect postitions to see what happens!

 

Quick update Myles, it ended up being half of V4 12AX7 was bad, all is well now and Trem channel is blasting away again..thanks for the advice and I did learn a couple of things along the way!

[blueross]

it is probably a microphonic tube

 

I finally spent some quality time trying to figure this out. The tube doesn't seem to be microphonic, per se, but it is a power tube. I turned the amp sideways and kept hitting a low G while putting gentle pressure on the tubes. The noise finally went away when I put pressure on (I think) V7. I think something is rattling in the base where the glass connects to the plastic.

 

So I'm pulling that and going to get some new power tubes. This one says J/J on it, not Groove Tube.

[myles_rose]

Ok thanks Myles, yeah I sure will do that, at least I know I have one good tube to swap around between the suspect postitions to see what happens!

 

Quick update Myles, it ended up being half of V4 12AX7 was bad, all is well now and Trem channel is blasting away again..thanks for the advice and I did learn a couple of things along the way!

 

 

Happy playing....

 

Myles

 

[myles_rose]

it is probably a microphonic tube

 

I finally spent some quality time trying to figure this out. The tube doesn't seem to be microphonic, per se, but it is a power tube. I turned the amp sideways and kept hitting a low G while putting gentle pressure on the tubes. The noise finally went away when I put pressure on (I think) V7. I think something is rattling in the base where the glass connects to the plastic.

 

So I'm pulling that and going to get some new power tubes. This one says J/J on it, not Groove Tube.

 

You may need to do nothing more than retension the tube socket that holds the offending tube.

 

 

[picker]

Hey Myles, I have a non-tube related question, but maybe it's some thing you can answer for me. I recently got a Variax to go with my POD XT Live, and the combination is sounding pretty good to me, given a few tweaks and changes here and there. I am curious if you can recommend a good way to amplify it, one that would get good acoustic guitar sounds as well as the electric sounds, which sound pretty good through a combo amp. Is there one amp out there that will deliver both?

[myles_rose]

Hey Myles, I have a non-tube related question, but maybe it's some thing you can answer for me. I recently got a Variax to go with my POD XT Live, and the combination is sounding pretty good to me, given a few tweaks and changes here and there. I am curious if you can recommend a good way to amplify it, one that would get good acoustic guitar sounds as well as the electric sounds, which sound pretty good through a combo amp. Is there one amp out there that will deliver both?

 

Just get a good solid state amp. I use a Carvin DCM-1000 for a lot of these sorts of applications. Not too heavy, very reliable and not pricy at all.

 

 

[Tone Taster]

 

Miles, regarding Buzzy Overdrive: What Mods ?

 

On a Sovtek Mig 60:

 

The "Buzziness" happens when I go into the low register power chords or when doing low register palm muted chugging

 

Does installing a PPIMV help this particular problem ?

 

What mods have you heard of to eliminate Buzzy overdrive on MV type Marshall circuits?

 

Regards,

Geoff J

[Sammyrama]

Hi Myles: My name is Sam,I live in San Luis Obispo,Ca. I am re-uniting with my band Sheister in Santa Barbara, Ca.I want a huge metal crunch and a very nice clean tone.What kind of set up would you recommend? Thanks!

[shood]

Myles,

 

I am retubing my Kingsley D32C (2 el84 & 2 6v6). I seem to recall that your favorite current-production el84 is the GT EL-84S, is that correct? What current-production 6v6 can you recommend?

 

Thank you!!! (BTW, I hope am am not borthering you unecessarily with this question - I looked for this info on your website but could not find it)

[haywired2]

I was going to replace the 12Ax7 in my 65 Vibrolux, but the Mesa Boogie or the Groove Tubes will not fit. They are fatter than the RCA that is in it and they won't fit in the socket. There is a metal shield around the socket that won't allow for a "Fatter" tube. Is there another brand or am I limited to the RCA?

 

Thanks

Scott

[myles_rose]

Miles, regarding Buzzy Overdrive: What Mods ?

 

On a Sovtek Mig 60:

 

The "Buzziness" happens when I go into the low register power chords or when doing low register palm muted chugging

 

Does installing a PPIMV help this particular problem ?

 

What mods have you heard of to eliminate Buzzy overdrive on MV type Marshall circuits?

 

Regards,

Geoff J

 

Just drop the gain in V1 a bit by using a selected tube and try a long plate such as a 12AX7R2