Feel free to ask Myles

[myles_rose]

Originally posted by mdrs:

Originally posted by myles111:

Originally posted by mdrs:

Thanks Myles! I didn't realize about the low voltage setting issue. Thanks for the heads up.

You are quite welcome.

 

Using a 12AY7 in V1 and 12AX7 in V2 with a 6V6 as the output tube is my personal favorite setup by the way.

 

You can also get a 8 to 9 pin adaptor and then also on the low setting use an EL84 and that is also a blast.

I'm in trouble!!

 

By the way, Mike was very quick to answer several e mails, and I've already placed an order! As a developing vintage "ampaholic", I thank you for your help, and appreciate the referal to Mike!

 

Now, I'll be e mailing Mike about the adaptor and the EL84.....

You are quite welcome.

[jzgtrguy]

Myles,

 

I have a Rivera Quiana Studio 112. Right now I am using GT 6L6GE's and GT12AX7M' in all pre-amp valve spots. I think my tubes are done because the amp is sounding like crap.

 

1) could you make some pre/amp tube suggestion for all five spaces?

2) is the 6L6GE still the best tube for this amp?

3) What about KT66hp's? Are they out of production? If so Where could I get some? Is there an equivelant?

 

Thanks,

Jeff

[myles_rose]

Originally posted by jzgtrguy:

Myles,

 

I have a Rivera Quiana Studio 112. Right now I am using GT 6L6GE's and GT12AX7M' in all pre-amp valve spots. I think my tubes are done because the amp is sounding like crap.

 

1) could you make some pre/amp tube suggestion for all five spaces?

2) is the 6L6GE still the best tube for this amp?

3) What about KT66hp's? Are they out of production? If so Where could I get some? Is there an equivelant?

 

Thanks,

Jeff

Jeff,

 

In your amp I prefer the 12AX7R3 in V1 and V2. The M is a bit dark for me in these amps for my current taste.

 

V3 and V4 are not critical ... reverb/effects loop.

 

In V5 I like a balanced 12AX7M or 12AX7R2 (Sovtek 12AX7LPS)

 

Output section .....

 

The KT66HP is history.

 

I use the 6L6GE's in a #6-7 rating biased at 34mA. The 6L6R2 (real Svetlana, not the Sovtek one) ... is also a favorite of mine there.

[Zephyr]

Myles, i would like your opinion on something:

 

For the coming holidays I am forced to make a decision between a Fender Hot Rod Deluxe and a Fender Deluxe Reverb (with an Ibanez Tube Screamer).

 

Which is the best for:

 

1)being there for a long period of time?

2)use as a practice amp?

3)The best overall tone?

[myles_rose]

Originally posted by Zephyr:

Myles, i would like your opinion on something:

 

For the coming holidays I am forced to make a decision between a Fender Hot Rod Deluxe and a Fender Deluxe Reverb (with an Ibanez Tube Screamer).

 

Which is the best for:

 

1)being there for a long period of time?

2)use as a practice amp?

3)The best overall tone?

This is totally my personal take on things which does not make it right but ...

 

more Fender Hot Rod Deluxe amps have been produced than any other amp in history. That has to say something. It is also a versitile amp with a master volume and overdrive channel.

 

But ... The BF Deluxe Reverb, for me, is one of the best sounding and most versitile amps ever made.

 

If it was me, I would pick the Deluxe Reverb. If it was up to Aspen Pittman of Groove Tubes, he would do the same as the DR is the amp that when he was asked, what single amp would you take to be stuck on a deserted island with, he said the Fender Black Face Deluxe reverb. This amp is also in his "top ten amps of all time" choice in The Tube Amp Book.

[Zephyr]

Thanks Myles, now I'm definitely going for the Reverb.

[WaterMan]

Myles,

 

Do you see any downside in using 5751s for both the V1 and PI in a 6L6, Class AB, non-negative feedback loop amp? If so, do you have a better suggestion? I'm trying to reduce pre-amp gain/distortion.

 

Thanks.

[myles_rose]

Originally posted by Zephyr:

Thanks Myles, now I'm definitely going for the Reverb.

Happy playing!

[myles_rose]

Originally posted by WaterMan:

Myles,

 

Do you see any downside in using 5751s for both the V1 and PI in a 6L6, Class AB, non-negative feedback loop amp? If so, do you have a better suggestion? I'm trying to reduce pre-amp gain/distortion.

 

Thanks.

None at all .... that is an old Stevie Ray Vaughn trick.

[WaterMan]

Originally posted by myles111:

Originally posted by WaterMan:

Myles,

 

Do you see any downside in using 5751s for both the V1 and PI in a 6L6, Class AB, non-negative feedback loop amp? If so, do you have a better suggestion? I'm trying to reduce pre-amp gain/distortion.

 

Thanks.

None at all .... that is an old Stevie Ray Vaughn trick.

Thanks Myles. And lastly on a related note, I'm having a hard time getting a succinct answer to this pre-amp tube question: In GENERAL, what are the gain ratings for these tube types? Does it go, from highest to lowest: 12AX7, 12AT7, 12AU7, 5751?

 

And, which types would you recommend/avoid in V1 and PI to reduce pre-amp gain, retain dynamics, and provide smooth, warm response? I know it's subjective to a degree, but I'm interested in your take. Thanks again.

[JP54]

Dear Myles

I'm waiting for delivery on a 57 Twin RI and happen to have pairs of some really good vintage tubes, both GE 6L6 AND, GEC KT 66's. I would esp love to use the KT 66's if that's possible.

1) I know that there's an adjustable bias POt, but manual is silent on how to do this. Anyone out there done this?

2) Anyone have experience with substituting KT 66's for 6l6's in a Twin RI? Advice? What/how to set Bias to? (6L6's are supposed to be 33.3 ma)

Finally, does touching the bias / adjustment VOID the WTTY?

Any help gratefully rec'd!!

Thanks

Jp

[myles_rose]

Originally posted by JP54:

Dear Myles

I'm waiting for delivery on a 57 Twin RI and happen to have pairs of some really good vintage tubes, both GE 6L6 AND, GEC KT 66's. I would esp love to use the KT 66's if that's possible.

1) I know that there's an adjustable bias POt, but manual is silent on how to do this. Anyone out there done this?

2) Anyone have experience with substituting KT 66's for 6l6's in a Twin RI? Advice? What/how to set Bias to? 6L6's are supposed to be 33.3 ma

Finally, does touching the bias / adjustment VOID the WTTY?

Any help gratefully rec'd!!

Thanks

Jp

Jp,

 

Just got your email on this and replied in the email.

 

I said this:

 

You can use thje KT66's but first run the bias down on the 6L6's so they are running very cold.

 

Most of the Fender amps have an internal test point on the left side of the horizontal board marked bias test. This sums the two tubes so we are looking at a setting of about 65mA here. If you have a bias tool or bias probe then you adjust for about 32-34mA per tube.

 

The reason we want the bias down at less than 20mA or so for one tube... is because a KT-66 can idle about 10mA higher than most 6L6s. If you plug them in and then go to adjust the bias they can be overdriven very quickly and strip some life off the cathode if they are way out of bias.

 

So ... lower the draw by increasing the voltage on pin 5 of the output tube socket to the highest negitive voltage, plug in the new KT66s and bring the bias back to where it should be.

 

You will not void the warranty by adjusting the bias.

 

If you contact Fender they should be able to email you a schematic that will have the bias test point and their recommended adjustment value.

[myles_rose]

Originally posted by WaterMan:

Originally posted by myles111:

Originally posted by WaterMan:

Myles,

 

Do you see any downside in using 5751s for both the V1 and PI in a 6L6, Class AB, non-negative feedback loop amp? If so, do you have a better suggestion? I'm trying to reduce pre-amp gain/distortion.

 

Thanks.

None at all .... that is an old Stevie Ray Vaughn trick.

Thanks Myles. And lastly on a related note, I'm having a hard time getting a succinct answer to this pre-amp tube question: In GENERAL, what are the gain ratings for these tube types? Does it go, from highest to lowest: 12AX7, 12AT7, 12AU7, 5751?

 

And, which types would you recommend/avoid in V1 and PI to reduce pre-amp gain, retain dynamics, and provide smooth, warm response? I know it's subjective to a degree, but I'm interested in your take. Thanks again.

I have this info somewhere on my website, maybe in the preamp tube area or tech area or tech tips area or who knows where in 450+ pages. So.... to make life a bit easier....

 

12AX7 gain 100

12AT7 gain 70 (but is an awful tone generator)

5751 gain 70

12AY7 gain 40 (the first gain stage of a tweed bassman and some other greats

12AU7 gain of about 16 and generally used as a phase inverter.

 

These are RCA/GE book spec from long ago. Current 12AX7's actually have a gain of between 80-85 on average these days with the exception of the Ei long smooth plates which do hit an actual gain of 100 in the standard lab test rig.

[picker]

12AX7 gain 100

12AT7 gain 70 (but is an awful tone generator)

5751 gain 70

12AY7 gain 40 (the first gain stage of a tweed bassman and some other greats

12AU7 gain of about 16 and generally used as a phase inverter.

 

Is a 12AU7 a good low-gain tone generator?

[ToadMeister]

posted 12-16-2006 04:21 PM

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

Miles,

 

I have a Rivera Clubster 45 I really enjoy this amp. Here's the problem. When playing at lower volume the amp sounds fantastic. I am able to get pinch harmonics at will. But when I turn it up to a fairly loud volume it is much harder to get pinch harmonics . . . It is almost like have a compressor maxed out in the chain to the point that the tone is squashed or compressed inhibiting the pinch harmonics. This is without any effects on except an old TubeScreamer with little or no drive and the output at about 3 o'clock using to boost the signal a bit this also happens without it on. And last but not least I play and old Strat.

 

Thank You

[myles_rose]

Originally posted by Picker:

12AX7 gain 100

12AT7 gain 70 (but is an awful tone generator)

5751 gain 70

12AY7 gain 40 (the first gain stage of a tweed bassman and some other greats

12AU7 gain of about 16 and generally used as a phase inverter.

 

Is a 12AU7 a good low-gain tone generator?

Not really. Keep it for phase inverter use.

 

12AY7 is great.

[myles_rose]

Originally posted by ToadMeister:

posted 12-16-2006 04:21 PM

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

Miles,

 

I have a Rivera Clubster 45 I really enjoy this amp. Here's the problem. When playing at lower volume the amp sounds fantastic. I am able to get pinch harmonics at will. But when I turn it up to a fairly loud volume it is much harder to get pinch harmonics . . . It is almost like have a compressor maxed out in the chain to the point that the tone is squashed or compressed inhibiting the pinch harmonics. This is without any effects on except an old TubeScreamer with little or no drive and the output at about 3 o'clock using to boost the signal a bit this also happens without it on. And last but not least I play and old Strat.

 

Thank You

You need a different 12AX7 in V1. You may have a tube that compresses too early from being a short plate tube or one that just has typical low current output down in the range of less than 0.8mA rather than a 1.2mA expected spec which is too often the case today with new production tubes. That is why every tube that goes into my clients amps is spec'd and documented before it goes in the amp.

[mudtone]

Myles,

 

Hello, I'm brand new at this, so sorry if I have not posted or replied correctly...

 

I got here by searching on "Carvin Nomad preamp distortion" in google...

 

My problem is that I'm getting a little distortion (not the good kind -this can't be intended -sounds like crap) from my stock 2005 Carvin Nomad on both the clean and dirty channels at very low volumes. Using any input (Epiphone Les Paul, Fender Strat, Green Bullet harp mic) I get some unwanted clipping/distortion when I play even kind-of heavy on my guitar (peaks), even when the amp's volume (clean channel or dirty) is down on about 2 -even if I turn the guitar's volume down a little.

I've also noticed that sometimes you can hear a quiet accompanying rattle/buzz/hum from the back of the amp that is not the speaker during these peaks.

 

I don't recall this problem always being there -that is to say I did not notice it when the amp was new. There is a little flabbyness to the speaker's low end, so that may have been disguising the problem.

 

I'm hoping the problem is a tube so I can fix it cheap-ish. I was thinking of swapping some of those small tubes (12AX7) around and see if I can isolate the problem tube, but don't know if this is wise, and can't find a diagram that shows what each tube if for.

 

Can you tell from this description what is going on and if a tube is the problem?

Thanks, Mudtone

[myles_rose]

Originally posted by mudtone:

Myles,

 

Hello, I'm brand new at this, so sorry if I have not posted or replied correctly...

 

I got here by searching on "Carvin Nomad preamp distortion" in google...

 

My problem is that I'm getting a little distortion (not the good kind -this can't be intended -sounds like crap) from my stock 2005 Carvin Nomad on both the clean and dirty channels at very low volumes. Using any input (Epiphone Les Paul, Fender Strat, Green Bullet harp mic) I get some unwanted clipping/distortion when I play even kind-of heavy on my guitar (peaks), even when the amp's volume (clean channel or dirty) is down on about 2 -even if I turn the guitar's volume down a little.

I've also noticed that sometimes you can hear a quiet accompanying rattle/buzz/hum from the back of the amp that is not the speaker during these peaks.

 

I don't recall this problem always being there -that is to say I did not notice it when the amp was new. There is a little flabbyness to the speaker's low end, so that may have been disguising the problem.

 

I'm hoping the problem is a tube so I can fix it cheap-ish. I was thinking of swapping some of those small tubes (12AX7) around and see if I can isolate the problem tube, but don't know if this is wise, and can't find a diagram that shows what each tube if for.

 

Can you tell from this description what is going on and if a tube is the problem?

Thanks, Mudtone

Your issue is output tubes not preamp tubes.

[mudtone]

Myles,

Thanks. The output tubes are the EL84s right? On this amp there are 4 Sovtek EL84/6BQ5 (04 05?)tubes.

 

Can I switch them around?

 

I think I read somewhere (maybe carvin's bbs) that you can remove 2 of the outer (or inner) tubes to half the amp's wattage, but you have to switch the ohms from 8 to either 16 or 4 (not sure which -very new at this) so as not to burn out the transformer...

 

do you think this method would work to determine which was the bad tube?

[myles_rose]

Originally posted by mudtone:

Myles,

Thanks. The output tubes are the EL84s right? On this amp there are 4 Sovtek EL84/6BQ5 (04 05?)tubes.

 

Can I switch them around?

 

I think I read somewhere (maybe carvin's bbs) that you can remove 2 of the outer (or inner) tubes to half the amp's wattage, but you have to switch the ohms from 8 to either 16 or 4 (not sure which -very new at this) so as not to burn out the transformer...

 

do you think this method would work to determine which was the bad tube?

Output tubes are the EL84's.

 

Switching them around will do nothing.

 

Do not remove ANY of them, this does not work on cathode biased amps as yours is.

 

You NEVER replace a single tube of a matched output set. Replace the entire set or you are just asking for trouble.

[tchipman]

Hi Myles,

I've got this question posted somewhere else as well but it was suggested that I ask you.

How much difference is there between the Celestion Blue speakers and the standard Vox custom speakers in an AC30 Custom Classic 2X12 combo.

I'd really like to have one but there's a huge difference in price for the Celestions.

Thanks

Tim

www.timothychipman.com

[myles_rose]

Originally posted by tchipman:

Hi Myles,

I've got this question posted somewhere else as well but it was suggested that I ask you.

How much difference is there between the Celestion Blue speakers and the standard Vox custom speakers in an AC30 Custom Classic 2X12 combo.

I'd really like to have one but there's a huge difference in price for the Celestions.

Thanks

Tim

www.timothychipman.com

This is really subjective but I personally feel there is a huge difference.

[Junior 1]

Hi Myles,

I'm getting a thin line acoustic electric and it comes in 2 versions. One has a bridge piezo pickup and the other a neck sound hole pickup. What can I expect the differences to be?

Thanks

Tony

[myles_rose]

Originally posted by Junior 1:

Hi Myles,

I'm getting a thin line acoustic electric and it comes in 2 versions. One has a bridge piezo pickup and the other a neck sound hole pickup. What can I expect the differences to be?

Thanks

Tony

This is like describing the difference between blue and green.

 

Go to a shop and play examples of both types.

[Junior 1]

Thanks Myles. You answered my question. If they're that close, I'd rather have a pickup attached to the outside of an inexspensive guitar than the inside of one.

[gtrwrks]

Myles,

 

I am looking for a recommendation for an output transformer for my Crate VFX5212. There is nothing 'wrong' with the stock unit, however I would like to improve the performance of the amp as much as possible.

 

I prefer plenty of clean headroom. I'm using this rebiased with 6L6s and 5751s in V1 and V2. I use this amp 12 - 15 nights a month playing pop and c&w jobs.

 

I am aware of Mercury Magnetics, am aware that you get what you pay for (most of the time); a more cost-effective alternative to the $200 MM would be helpful.

 

Any help that you'd be willing to share would be appreciated.

 

Thank you.

[myles_rose]

Originally posted by gtrwrks:

Myles,

 

I am looking for a recommendation for an output transformer for my Crate VFX5212. There is nothing 'wrong' with the stock unit, however I would like to improve the performance of the amp as much as possible.

 

I prefer plenty of clean headroom. I'm using this rebiased with 6L6s and 5751s in V1 and V2. I use this amp 12 - 15 nights a month playing pop and c&w jobs.

 

I am aware of Mercury Magnetics, am aware that you get what you pay for (most of the time); a more cost-effective alternative to the $200 MM would be helpful.

 

Any help that you'd be willing to share would be appreciated.

 

Thank you.

A MM transformer is the biggest single improvement you could make to your amp.

 

Call over to MM and ask for Patrick.

[picker]

Myles,

I just got an SWR SM 500 bass amp, which has one 12AX7 in the preamp. A guy at the Guitar Center I bought it used from told me to replace the stock tube with a GT Gold Series GT ECC83. Do you agree with that, and why?

[myles_rose]

Originally posted by Picker:

Myles,

I just got an SWR SM 500 bass amp, which has one 12AX7 in the preamp. A guy at the Guitar Center I bought it used from told me to replace the stock tube with a GT Gold Series GT ECC83. Do you agree with that, and why?

The ECC83S has a mid bump that is cool in the front end of British voiced amps .... Marshall ... Vox.

 

I would not use in the SWR. In your amp I would use a smooth and linear 12AX7C