Feel free to ask Myles

[myles_rose]

Originally posted by strat monk:

Hey Myles:

 

Hope you had a great new year. I have another question about my Mesa/Boogie F-100. It has the half power switch (100/60 watts) and I often switch between the two wattages because of different playing situations. Is this bad for the tubes at all? I'm probably just being paranoid but thanks in advance.

strat monk.........

 

Not bad for the tubes at all, but if you play a lot of hours in the half power mode, swap the inner and outer pairs every now and then to keep the tube wear even as one pair is not being used at all.

[Jazz Guitar]

Originally posted by myles111:

Originally posted by jetboy:

[qb]

jetboy .... okay .... I will take a

 

The EL34 is a BIG part of the problem. Try a good 6L6.

 

The preamp tube changes will help even more.

Hey Myles. If you're up to sporting dumb questions, can you tell me why tube amps "need" a phase splitter? Push-pull transistor amps have no such need. Sorry, they didn't teach us tubes in school, except for a little CRT stuff.

 

See, there was a need for Latin and tubes after all. Calculus too.

[myles_rose]

Originally posted by Mr Nice Jazz Guitar Guy:

Originally posted by myles111:

Originally posted by jetboy:

[qb]

jetboy .... okay .... I will take a

 

The EL34 is a BIG part of the problem. Try a good 6L6.

 

The preamp tube changes will help even more.

Hey Myles. If you're up to sporting dumb questions, can you tell me why tube amps "need" a phase splitter? Push-pull transistor amps have no such need. Sorry, they didn't teach us tubes in school, except for a little CRT stuff.

 

See, there was a need for Latin and tubes after all. Calculus too.

Download part 2 of my tube amp primer off my website, it is all there.

[Jazz Guitar]

Download part 2 of my tube amp primer off my website, it is all there.[/QB]

 

I looked on page 52, but that didn't really explain the usage or rationale of the phase inverter.

[leadfootdriver]

Hey Myles. I just got wind of the new GT "Mullard" 12AX7's.

 

Well, how are they?

[myles_rose]

Originally posted by Mr Nice Jazz Guitar Guy:

Download part 2 of my tube amp primer off my website, it is all there.

 

I looked on page 52, but that didn't really explain the usage or rationale of the phase inverter.[/QB]

 

It is a very long explanation and it will be in many areas, not just on one page.

[myles_rose]

Originally posted by leadfootdriver:

Hey Myles. I just got wind of the new GT "Mullard" 12AX7's.

 

Well, how are they?

Lots of info on my website and lots of Tom Dunn feedback on Harmony Central and in the PRS Forum.

[leadfootdriver]

Originally posted by myles111:

Originally posted by leadfootdriver:

Hey Myles. I just got wind of the new GT "Mullard" 12AX7's.

 

Well, how are they?

Lots of info on my website and lots of Tom Dunn feedback on Harmony Central and in the PRS Forum.

Thanks Myles! They sound promising. I'm open to try a set.

[leadfootdriver]

You are the man Myles. The information on your site, is the education in tubes that I never had.

 

I guess I don't miss, what I've never known. I'm anxious to try a set of the Mullard NVM 12AX7's. I'm sure they won't be going for $90 a piece, like I've seen the NOS pieces are going for lately. So this will probably be huge for GT!

[myles_rose]

Originally posted by leadfootdriver:

You are the man Myles. The information on your site, is the education in tubes that I never had.

 

I guess I don't miss, what I've never known. I'm anxious to try a set of the Mullard NVM 12AX7's. I'm sure they won't be going for $90 a piece, like I've seen the NOS pieces are going for lately. So this will probably be huge for GT!

$26.00 list, and they start shipping late February.

[snoz65]

Heya Miles.

I recently checked the bias in my Marshall 30th anniversary and found one tube to be drawing 10mA more than the other. I have two (50W Mode) 6L6STR Harma's in there, about 12 months old.

I figure that a new set of tubes is due and probaby a 12ax7MPI.

Can you see a pair of NOS 6L6WGB JAN GE's being a marked improvement over the Harmas in my amp (when they were matched)?

Plate voltage is 470-480V and I don't mind some earlier break up and lower output.

Besides that, do you know of a source of pre '02 Svet 6L6GC's? They were much warmer than the Harmas.

Thanks,

Shaun.

[myles_rose]

Originally posted by snoz65:

Heya Miles.

I recently checked the bias in my Marshall 30th anniversary and found one tube to be drawing 10mA more than the other. I have two (50W Mode) 6L6STR Harma's in there, about 12 months old.

I figure that a new set of tubes is due and probaby a 12ax7MPI.

Can you see a pair of NOS 6L6WGB JAN GE's being a marked improvement over the Harmas in my amp (when they were matched)?

Plate voltage is 470-480V and I don't mind some earlier break up and lower output.

Besides that, do you know of a source of pre '02 Svet 6L6GC's? They were much warmer than the Harmas.

Thanks,

Shaun.

Shaun,

 

Ten mA in a static state is getting to be a wide spread. The Harma tubes are generally JJ tubes that have been selected very closely. The JJ tubes do need a bit more burn in than many other tubes to stabilize. On new Harma tubes, you may want ot check and possibly readjust the bias after the first 25 or so hours of playing.

 

The JAN Philips NOS WGB is a killer tube. I personally would prefer this tube. This though boils down to personal preference.

 

The true Svet date codes are not an issue if you get these from a vendor that tests for low vacuum. If the svets have proper vacuum, then they are just as nice as any other year or production run.

 

If you liked the Svets, maybe check with some folks on their feeling on the GT-6L6GE.

[snoz65]

The JAN Philips NOS WGB is a killer tube. I personally would prefer this tube. This though boils down to personal preference.

 

The true Svet date codes are not an issue if you get these from a vendor that tests for low vacuum. If the svets have proper vacuum, then they are just as nice as any other year or production run.

 

If you liked the Svets, maybe check with some folks on their feeling on the GT-6L6GE.

Thanks Miles, I have ordered a couple of GT-6L6GE's and a SAG12ax7MPI.

 

I'm not sure that I realy want earlier power tube break up now so I'll give the 6L6WGB's a miss, for now.

 

Shaun.

 

P.S. Congrats on the best forum thread on the net!

[myles_rose]

Originally posted by snoz65:

The JAN Philips NOS WGB is a killer tube. I personally would prefer this tube. This though boils down to personal preference.

 

The true Svet date codes are not an issue if you get these from a vendor that tests for low vacuum. If the svets have proper vacuum, then they are just as nice as any other year or production run.

 

If you liked the Svets, maybe check with some folks on their feeling on the GT-6L6GE.

Thanks Miles, I have ordered a couple of GT-6L6GE's and a SAG12ax7MPI.

 

I'm not sure that I realy want earlier power tube break up now so I'll give the 6L6WGB's a miss, for now.

 

Shaun.

 

P.S. Congrats on the best forum thread on the net!

Shaun,

 

On your tubes, I will track down the order and match the rise time of the MPI to the GE's. This takes about 45 minutes, but is a cool way to go.

 

My treat.

[steve f]

Myles,

 

Since you're on the topic of 30th Anniversary Marshalls. Would NOS Tung-Sol 5881s be ok in one of these? I know some of the older 6L6 class tubes weren't meant for higher plate voltages that modern amps have.

[Jazz Guitar]

Originally posted by myles111:

Originally posted by Caevan O'Shite:

Hey, Myles, big dumb question time:

Caevan O'Shite...........

Well I won't touch that......

 

Hey Myles, who had the first master volume amps? Boogie? Traynor? Bogen?

[mstreck]

Myles,

 

I just bought a Fender Cyber-Twin from Musician's Friend. The Master Volume is not working correctly. I have to turn it to 7 to get it to about a third volume. At 7 and a half it jumps up to almost full volume. There is no in-between.

 

Any ideas? Or should I just send it back?

 

Thanks,

 

Mike

[snoz65]

Shaun,

 

On your tubes, I will track down the order and match the rise time of the MPI to the GE's. This takes about 45 minutes, but is a cool way to go.

 

My treat.

Wow

Your a real gentleman Myles, Thank you very much.

 

Shaun.

[myles_rose]

Originally posted by steve f:

Myles,

 

Since you're on the topic of 30th Anniversary Marshalls. Would NOS Tung-Sol 5881s be ok in one of these? I know some of the older 6L6 class tubes weren't meant for higher plate voltages that modern amps have.

Steve,

 

The Tung Sol 5881 is considered by a lot of folks, one of the best, if not the best, 6L6 type tube ever made.

 

In your amp, biased at 60% ID, it is quite amazing.

[myles_rose]

Originally posted by Mr Nice Jazz Guitar Guy:

Originally posted by myles111:

Originally posted by Caevan O'Shite:

Hey, Myles, big dumb question time:

Caevan O'Shite...........

Well I won't touch that......

 

Hey Myles, who had the first master volume amps? Boogie? Traynor? Bogen?

Mr Nice Jazz Guitar Guy...........

 

You know what? I do not know.

 

Maybe some great amp historian around will have the answer to that one!

[myles_rose]

Originally posted by mstreck:

Myles,

 

I just bought a Fender Cyber-Twin from Musician's Friend. The Master Volume is not working correctly. I have to turn it to 7 to get it to about a third volume. At 7 and a half it jumps up to almost full volume. There is no in-between.

 

Any ideas? Or should I just send it back?

 

Thanks,

 

Mike

Mike,

 

It could be many things. There is a lot of DSP stuff going on in these amps. I would send it back for warranty repair or replacement.

[myles_rose]

Originally posted by snoz65:

Shaun,

 

On your tubes, I will track down the order and match the rise time of the MPI to the GE's. This takes about 45 minutes, but is a cool way to go.

 

My treat.

Wow

Your a real gentleman Myles, Thank you very much.

 

Shaun.

Shaun,

 

No problem ... keep it quiet though, as they normally charge more for that.

[Caevan O’Shite]

Originally posted by Mr Nice Jazz Guitar Guy:

 

Originally posted by Caevan O'Shite:

"Hey, Myles, big dumb question time:

 

Caevan O'Shite...........

Originally posted by Mr Nice Jazz Guitar Guy:

"Well I won't touch that......"

MrNJGG, must you be such an arrogant and provoking horse's ass?

 

It's one thing to play around and even be abjectly rude on the open forum-proper; it's another to do so within this thread.

 

If you've got a helpful, insightful reply that will lighten Myles' workload and answer a posted question, by all means, do so.

 

If you're going to dick around in a smug, smarmy, teacher's pet affectation, then, by all means, shut up for once in your life. Bullshit is bullshit.

 

Oops, my apologies to any horses who might be reading this...

 

I apologize for this interuption and reactionary posting, Myles, but I've gotta make the call this way, this time.

 

Now back to our regular program...

[mstreck]

Originally posted by myles111:

Originally posted by mstreck:

Myles,

 

I just bought a Fender Cyber-Twin from Musician's Friend. The Master Volume is not working correctly. I have to turn it to 7 to get it to about a third volume. At 7 and a half it jumps up to almost full volume. There is no in-between.

 

Any ideas? Or should I just send it back?

 

Thanks,

 

Mike

Mike,

 

It could be many things. There is a lot of DSP stuff going on in these amps. I would send it back for warranty repair or replacement.

Thanks. That's what I did today. The new one should be here in a few days. Someone told me it was a bad pot but it's not a simple replacement procedure (since it's motorized).

 

Damn technology!

[mherrcat]

I have a Mesa/Boogie MKIIb with an 8 Ohm EV12L speaker. Mesa recommends using the 4 Ohm speaker jack when in the 60 watt power mode.

 

If I were to use a THD Hot Plate, would I need to get the 8 Ohm model and still plug it into the 4 Ohm speaker jack?

 

Also, when using Yellow Jackets in the outside tube positions (for 60 watt mode) do I want to avoid switching to the 100 watt mode?

[myles_rose]

Originally posted by mstreck:

Originally posted by myles111:

Originally posted by mstreck:

Myles,

 

I just bought a Fender Cyber-Twin from Musician's Friend. The Master Volume is not working correctly. I have to turn it to 7 to get it to about a third volume. At 7 and a half it jumps up to almost full volume. There is no in-between.

 

Any ideas? Or should I just send it back?

 

Thanks,

 

Mike

Mike,

 

It could be many things. There is a lot of DSP stuff going on in these amps. I would send it back for warranty repair or replacement.

Thanks. That's what I did today. The new one should be here in a few days. Someone told me it was a bad pot but it's not a simple replacement procedure (since it's motorized).

 

Damn technology!

Sometimes there is infant mortality with new complex devices. If you get past 90 days or so, then you can expect great service for many years.

[myles_rose]

Originally posted by mherrcat:

I have a Mesa/Boogie MKIIb with an 8 Ohm EV12L speaker. Mesa recommends using the 4 Ohm speaker jack when in the 60 watt power mode.

 

If I were to use a THD Hot Plate, would I need to get the 8 Ohm model and still plug it into the 4 Ohm speaker jack?

 

Also, when using Yellow Jackets in the outside tube positions (for 60 watt mode) do I want to avoid switching to the 100 watt mode?

mherrcat...........

 

In the half power mode (60 watt) you do use the 4 ohm tap as there are half the output tubes on line.

 

With a hot plate, use an 8 ohm hotplate in the 8 ohm jack in 100 watt mode.

 

Using Yellow Jackets, you do want to use these in the 100 watt mode if all four tubes (two of the Mesa tubes and two yellow jackets) are used.

[Jazz Guitar]

Originally posted by myles111:

Originally posted by mherrcat:

[qb]I have a Mesa/Boogie MKIIb with an 8 Ohm EV12L speaker. Mesa recommends using the 4 Ohm speaker jack when in the 60 watt power mode.

 

If I were to use a THD Hot Plate, would I need to get the 8 Ohm model and still plug it into the 4 Ohm speaker jack?

Oh Myles, why is it necessary to always have a load connected to a tube amp, when it's perfectly safe to powerup a transistor amp with no load?

 

Also, if memory serves, tubes need a transformer on the output for impedence matching, where transistor amp have no need of this. Why is that?

 

They didn't teach us tubes in school.

[myles_rose]

Originally posted by Mr Nice Jazz Guitar Guy:

Originally posted by myles111:

Originally posted by mherrcat:

[qb]I have a Mesa/Boogie MKIIb with an 8 Ohm EV12L speaker. Mesa recommends using the 4 Ohm speaker jack when in the 60 watt power mode.

 

If I were to use a THD Hot Plate, would I need to get the 8 Ohm model and still plug it into the 4 Ohm speaker jack?

Oh Myles, why is it necessary to always have a load connected to a tube amp, when it's perfectly safe to powerup a transistor amp with no load?

 

Also, if memory serves, tubes need a transformer on the output for impedence matching, where transistor amp have no need of this. Why is that?

 

They didn't teach us tubes in school.

Tube do need a load, i.e., transformer in most cases.

 

Transistors can be direct coupled to capacitor coupled.

 

This is all covered in detail in my Tube Primer section II.

[Jazz Guitar]

Originally posted by myles111:

Originally posted by Mr Nice Jazz Guitar Guy:

Originally posted by myles111:

Originally posted by mherrcat:

[qb]I have a Mesa/Boogie MKIIb with an 8 Ohm EV12L speaker. Mesa recommends using the 4 Ohm speaker jack when in the 60 watt power mode.

 

If I were to use a THD Hot Plate, would I need to get the 8 Ohm model and still plug it into the 4 Ohm speaker jack?

Oh Myles, why is it necessary to always have a load connected to a tube amp, when it's perfectly safe to powerup a transistor amp with no load?

 

Also, if memory serves, tubes need a transformer on the output for impedence matching, where transistor amp have no need of this. Why is that?

 

They didn't teach us tubes in school.

Tube do need a load, i.e., transformer in most cases.

 

Transistors can be direct coupled to capacitor coupled.

 

This is all covered in detail in my Tube Primer section II.

Hey Myles, do you like the Monteleone pics? I think this one is a "Radio Flyer", going for a paultry 15 grand. If this was 1999 all over again, I'd actually consider it!