Feel free to ask Myles

[myles_rose]

Originally posted by blues&swing:

Hi Myles,

 

I an really a novice to this website but I am impressed about the number of people participating and about the pro advice I have received so far. I have here a couple of questions that you probably are one of the most experienced individuals to anwer to:

- I have a Laney LC15 15W tube combo. I play it upside down since I want the tubes to release heat upwards (PCB is on the top (in normal position) and tubes are attached to it. The tubes have clips that hold them in place. When the amp is placed in any position there is a pretty high frequency "sizzling" noice heard from the amp -- difficult to say if it it mechanical and electronical noice. What could be causing this noice? Could it be a symptom of old tubes that need replacement? Or perhaps the holding clips are causing the noise? Are there any ways to isolate the cause? In general, when do you know if tubes need to be replaced?

- Secondly, I also have a Tube Works hybrid combo (tube preamp, solid state power amp)and when I place it on a tilted amp stand its reverb does not funtion at all. In a straight vertical position there are no problems whatsoever. Is it common for amps with spring reverb do this?

 

Thank you very much for you advice, in advance!

 

Edit: I place these questions to the general guitar forum too.

To find buzzes and the like you need to hook the amp up to a signal generator, sweep it at moderate levels and push here and there without getting zapped (a wood stick works) to find the culprit(s)

[exactopposite]

hey myles

 

i got a preamp tube as a part of a trade and i'd like to get some info on it

 

the wrting on the tube says:

 

NATIONAL

6681

MADE IN USA

 

i put it in my amp and it works and sounds great i'm just curious to know more about it. i'd appeciate any info you have on the topic.

[myles_rose]

Originally posted by exactopposite:

hey myles

 

i got a preamp tube as a part of a trade and i'd like to get some info on it

 

the wrting on the tube says:

 

NATIONAL

6681

MADE IN USA

 

i put it in my amp and it works and sounds great i'm just curious to know more about it. i'd appeciate any info you have on the topic.

This is just a industrial 12AX7 designation. It has no special merit from a high $$$ point and may just be work keeping if you like it sonically.

[exactopposite]

Originally posted by myles111:

Originally posted by exactopposite:

hey myles

 

i got a preamp tube as a part of a trade and i'd like to get some info on it

 

the wrting on the tube says:

 

NATIONAL

6681

MADE IN USA

 

i put it in my amp and it works and sounds great i'm just curious to know more about it. i'd appeciate any info you have on the topic.

This is just a industrial 12AX7 designation. It has no special merit from a high $$$ point and may just be work keeping if you like it sonically.

thanx. i just traded someone a pair of 6l6's for a couple of preamp tubes because i don't own a 6l6 amp and i had no use for the tubes. the tubes i traded were mesa str 420's that i only had for spares. they are nothing to write home about so i can't complain about what i got for em. i just wanted to get something for them instead of throwing them away.

thanx for the info

[Jazz Guitar]

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

[exactopposite]

Originally posted by Jazz Guitar:

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

there is some info at this link on myles website about how the gt scale relates to the mesa boogie tube color code. pretty much the tubes the boogie sell are in the 4-6 range of gt tubes. http://www.guitaramplifierblueprinting.com/pastinfo.html

[Jazz Guitar]

Originally posted by exactopposite:

Originally posted by Jazz Guitar:

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

there is some info at this link on myles website about how the gt scale relates to the mesa boogie tube color code. pretty much the tubes the boogie sell are in the 4-6 range of gt tubes. http://www.guitaramplifierblueprinting.com/pastinfo.html

Thanks, but I think I did recall seeing that long ago and that's where I got that figure of "6". Probably should be a "5".

 

I also brushed up on the balanced phase inverter tube aspects. Sometimes some of the NOS websites will offer a balanced PI for a few bucks more.

[exactopposite]

Originally posted by Jazz Guitar:

Originally posted by exactopposite:

Originally posted by Jazz Guitar:

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

there is some info at this link on myles website about how the gt scale relates to the mesa boogie tube color code. pretty much the tubes the boogie sell are in the 4-6 range of gt tubes. http://www.guitaramplifierblueprinting.com/pastinfo.html

Thanks, but I think I did recall seeing that long ago and that's where I got that figure of "6". Probably should be a "5".

 

I also brushed up on the balanced phase inverter tube aspects. Sometimes some of the NOS websites will offer a balanced PI for a few bucks more.

no prob. i remember asking him about it when i had a boogie.

[myles_rose]

Originally posted by Jazz Guitar:

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

Mesa vs Groove Tubes scale

Red 4

Yellow 4

Green 5

Gray 5

Blue 6

White 6

[Jazz Guitar]

Originally posted by exactopposite:

Originally posted by Jazz Guitar:

Originally posted by exactopposite:

quote:

---

Originally posted by Jazz Guitar:

Myles, if a Boogie owner were interested in a pair of GT 6L6GEs, what would you recommend, keeping in mind the non-adjustable bias? I figure Boogie's fixed bias setting allows for considerable "slop" and a pair of the GT 6L6GEs with a "hardness" of about 6 should do quite nicely, as long as they were a matched pair.

there is some info at this link on myles website about how the gt scale relates to the mesa boogie tube color code. pretty much the tubes the boogie sell are in the 4-6 range of gt tubes.

http://www.guitaramplifierblueprinting.com/pastinfo.html

Thanks, but I think I did recall seeing that long ago and that's where I got that figure of "6". Probably should be a "5".

 

I also brushed up on the balanced phase inverter tube aspects. Sometimes some of the NOS websites will offer a balanced PI for a few bucks more.

no prob. i remember asking him about it when i had a boogie.

---

Past tense? What happened?

[sgguitarzz]

I am not sure if you saw my question Myles so I will try again. I just picked up a Sunn T50C off of Ebay and it has all the original crappy stock Sovteks. Any recommendations for tubes in these amps. I know there are some similarities between these and the Fender Pro Reverb Tubes series. It has a nice clean but the OD channel is very gainy. I think this amp has alot of potential with a few changes. I was also thinking of changing out the Celestion speaker to a Reverend Alltone 1250 which might be a little smoother. Any suggestions would be appreciated.

Also, I just put in a pair of JJ 6L6GC's and cannot adjust the bias above 24mVDC. The Sovteks were running at 41mVDC. The Sunn manual says to set the bias for 30mVDC. There are bias and balance controls on the back of the amp. I bought a Craftsman multimeter and this is the first time I have tried this. Seems pretty simple. Any suggestions? Thanks.

Thanks.

[exactopposite]

Originally posted by Jazz Guitar:

Past tense? What happened?

well that was a couple of years ago. i had to sell it to pay the rent. this was after my job moved to mexico and i got denied by nafta. shit happens. i'll have another one.

[myles_rose]

Originally posted by sgguitarzz:

I am not sure if you saw my question Myles so I will try again. I just picked up a Sunn T50C off of Ebay and it has all the original crappy stock Sovteks. Any recommendations for tubes in these amps. I know there are some similarities between these and the Fender Pro Reverb Tubes series. It has a nice clean but the OD channel is very gainy. I think this amp has alot of potential with a few changes. I was also thinking of changing out the Celestion speaker to a Reverend Alltone 1250 which might be a little smoother. Any suggestions would be appreciated.

Also, I just put in a pair of JJ 6L6GC's and cannot adjust the bias above 24mVDC. The Sovteks were running at 41mVDC. The Sunn manual says to set the bias for 30mVDC. There are bias and balance controls on the back of the amp. I bought a Craftsman multimeter and this is the first time I have tried this. Seems pretty simple. Any suggestions? Thanks.

Thanks.

This sounds like the JJs are pretty weak.

 

I prefer GEs or KT66HPs in the amp at 30mA.

 

V1 I use a 12AX7C or the new 12AX7M, V2 a 12AY7 actually. Matched phase inverter too.

[njrocker]

just noticing that this thread has over 2000 replies now

[Guitar Geezer]

Hi Myles

Just a curious question. What is the "Relationship" between Crate, and the Vseries GT amps? Meaning---Are they manufactured in the same place - or is someone else producing them for Crate? The two are such opposite in terms of sound and quality IMHO.

No biggie, just wondering.

LynnG

[sgguitarzz]

Thanks.[/qb]

This sounds like the JJs are pretty weak.

 

I prefer GEs or KT66HPs in the amp at 30mA.

 

V1 I use a 12AX7C or the new 12AX7M, V2 a 12AY7 actually. Matched phase inverter too.[/QB]

 

The JJ's are brand new. Maybe I should send them back if possible and exchange them for other power tubes. I just received the 12AX7M and will try it in V1. I also put in a balanced PI as well. I put in a Mullard CV4024 for the reverb driver. Definitely better than the GT 12AT7 that was there before.I put JJ's in V4,V6 and V7.

Thanks very much for the suggestions.

[myles_rose]

Originally posted by njrocker:

just noticing that this thread has over 2000 replies now

njrocker ..........

 

Lots of questions and answers I guess!

[myles_rose]

Originally posted by guitar geezer:

Hi Myles

Just a curious question. What is the "Relationship" between Crate, and the Vseries GT amps? Meaning---Are they manufactured in the same place - or is someone else producing them for Crate? The two are such opposite in terms of sound and quality IMHO.

No biggie, just wondering.

LynnG

Lynn,

 

I really do not know.

 

Sorry.

[myles_rose]

Originally posted by sgguitarzz:

Thanks.

This sounds like the JJs are pretty weak.

 

I prefer GEs or KT66HPs in the amp at 30mA.

 

V1 I use a 12AX7C or the new 12AX7M, V2 a 12AY7 actually. Matched phase inverter too.[/QB]

 

The JJ's are brand new. Maybe I should send them back if possible and exchange them for other power tubes. I just received the 12AX7M and will try it in V1. I also put in a balanced PI as well. I put in a Mullard CV4024 for the reverb driver. Definitely better than the GT 12AT7 that was there before.I put JJ's in V4,V6 and V7.

Thanks very much for the suggestions.[/QB]

 

You are more than welcome.

[sgguitarzz]

I was just curious what the difference was between the KT66HP's and 6L6's in general and if I were to get a set of KT66HP's what should the tubes be rated at (4,5,6, etc).

Also, I had the amp all set and sounding pretty nice. I put in some Svetlana 6L6's I had and biased them at 30mA. I then tried throwing in some Yellowjackets just to see how they would sound and something must have blown because the power tube trouble light stays lit red all the time now even with other power tubes in there and there is extremely low distorted output. Fender was no help so I took it in to a tech to check out. I guess sometimes a little knowledge can be dangerous . Hopefully it won't be too bad. I have no luck sometimes.

 

Originally posted by myles111:

Originally posted by sgguitarzz:

Thanks.

This sounds like the JJs are pretty weak.

 

I prefer GEs or KT66HPs in the amp at 30mA.

 

V1 I use a 12AX7C or the new 12AX7M, V2 a 12AY7 actually. Matched phase inverter too.

The JJ's are brand new. Maybe I should send them back if possible and exchange them for other power tubes. I just received the 12AX7M and will try it in V1. I also put in a balanced PI as well. I put in a Mullard CV4024 for the reverb driver. Definitely better than the GT 12AT7 that was there before.I put JJ's in V4,V6 and V7.

Thanks very much for the suggestions.[/QB]

 

You are more than welcome.[/QB]

[njrocker]

Miles,

 

I bought my first tube amp, a 40 watt Fender Hot Rod Deluxe, a few months ago. Why does this amp have 3 12AX7's? I don't have much experience with tube amps, but it seems kind of odd to have 3 12AX7's. Don't most amps have 2? Also, the drive channel is pretty lame. How could I tighten up the bass and get a better bluesy grind type sound? Maybe the speaker?

 

Also, the amp has two Groove Tubes 6L6's(red) and a solid state rectifier. All of the tubes are Russian.

[bluesswing]

quote:

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

Originally posted by blues&swing:

Hi Myles,

 

I an really a novice to this website but I am impressed about the number of people participating and about the pro advice I have received so far. I have here a couple of questions that you probably are one of the most experienced individuals to anwer to:

- I have a Laney LC15 15W tube combo. I play it upside down since I want the tubes to release heat upwards (PCB is on the top (in normal position) and tubes are attached to it. The tubes have clips that hold them in place. When the amp is placed in any position there is a pretty high frequency "sizzling" noice heard from the amp -- difficult to say if it it mechanical and electronical noice. What could be causing this noice? Could it be a symptom of old tubes that need replacement? Or perhaps the holding clips are causing the noise? Are there any ways to isolate the cause? In general, when do you know if tubes need to be replaced?

- Secondly, I also have a Tube Works hybrid combo (tube preamp, solid state power amp)and when I place it on a tilted amp stand its reverb does not funtion at all. In a straight vertical position there are no problems whatsoever. Is it common for amps with spring reverb do this?

 

Thank you very much for you advice, in advance!

 

Edit: I place these questions to the general guitar forum too.

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

 

To find buzzes and the like you need to hook the amp up to a signal generator, sweep it at moderate levels and push here and there without getting zapped (a wood stick works) to find the culprit(s)

 

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

Myles S. Rose

QUOTE

Hi Myles,

 

I apologize for this delay in replying -- I meanwhile added a connector for external speaker cabinet to the amp and I can see that the hi-freq noise is there only if I use the amp's internal speaker or have the amp sitting on top of the speaker cabinet. Are aging tubes vulnerable to external vibration that may cause this or do you think the cause may be tube clips that vibrate when paying through the amp? Do you still recommend me to push components for troubleshooting or is the presence of external vibration anough to find the problem?

 

Tks

blues&swing

[Darklava]

Hi myles I have a mesa DC5 that seems to go in to boost mode by it self could it be just the knob

or do you think I have big problems?I just bought

the amp so I still have time to take it back.

[Caevan O’Shite]

DARKLAVA- Did you buy that amp brand-new? If so, if there's any problem, take it right back! Don't risk voiding your warranty; go back to the store with it, and don't take any runaround crap. I mean, be polite and all, but don't let somebody talk you out of a replacement or factory-authorized fix, O.K.?

 

I think that Myles will agree with me here, as well.

[myles_rose]

Originally posted by sgguitarzz:

I was just curious what the difference was between the KT66HP's and 6L6's in general and if I were to get a set of KT66HP's what should the tubes be rated at (4,5,6, etc).

Also, I had the amp all set and sounding pretty nice. I put in some Svetlana 6L6's I had and biased them at 30mA. I then tried throwing in some Yellowjackets just to see how they would sound and something must have blown because the power tube trouble light stays lit red all the time now even with other power tubes in there and there is extremely low distorted output. Fender was no help so I took it in to a tech to check out. I guess sometimes a little knowledge can be dangerous . Hopefully it won't be too bad. I have no luck sometimes.

 

Originally posted by myles111:

Originally posted by sgguitarzz:

Thanks.

This sounds like the JJs are pretty weak.

 

I prefer GEs or KT66HPs in the amp at 30mA.

 

V1 I use a 12AX7C or the new 12AX7M, V2 a 12AY7 actually. Matched phase inverter too.

The JJ's are brand new. Maybe I should send them back if possible and exchange them for other power tubes. I just received the 12AX7M and will try it in V1. I also put in a balanced PI as well. I put in a Mullard CV4024 for the reverb driver. Definitely better than the GT 12AT7 that was there before.I put JJ's in V4,V6 and V7.

Thanks very much for the suggestions.

You are more than welcome.[/QB][/QB]

 

You have a lot in here that would take a lot to answer and discuss.

 

Call me toll free after Tuesday at 1-800-459-5687.

[myles_rose]

Originally posted by njrocker:

Miles,

 

I bought my first tube amp, a 40 watt Fender Hot Rod Deluxe, a few months ago. Why does this amp have 3 12AX7's? I don't have much experience with tube amps, but it seems kind of odd to have 3 12AX7's. Don't most amps have 2? Also, the drive channel is pretty lame. How could I tighten up the bass and get a better bluesy grind type sound? Maybe the speaker?

 

Also, the amp has two Groove Tubes 6L6's(red) and a solid state rectifier. All of the tubes are Russian.

Look at my tube primer off my GAB website.

[myles_rose]

Originally posted by blues&swing:

quote:

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

Originally posted by blues&swing:

Hi Myles,

 

I an really a novice to this website but I am impressed about the number of people participating and about the pro advice I have received so far. I have here a couple of questions that you probably are one of the most experienced individuals to anwer to:

- I have a Laney LC15 15W tube combo. I play it upside down since I want the tubes to release heat upwards (PCB is on the top (in normal position) and tubes are attached to it. The tubes have clips that hold them in place. When the amp is placed in any position there is a pretty high frequency "sizzling" noice heard from the amp -- difficult to say if it it mechanical and electronical noice. What could be causing this noice? Could it be a symptom of old tubes that need replacement? Or perhaps the holding clips are causing the noise? Are there any ways to isolate the cause? In general, when do you know if tubes need to be replaced?

- Secondly, I also have a Tube Works hybrid combo (tube preamp, solid state power amp)and when I place it on a tilted amp stand its reverb does not funtion at all. In a straight vertical position there are no problems whatsoever. Is it common for amps with spring reverb do this?

 

Thank you very much for you advice, in advance!

 

Edit: I place these questions to the general guitar forum too.

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

 

To find buzzes and the like you need to hook the amp up to a signal generator, sweep it at moderate levels and push here and there without getting zapped (a wood stick works) to find the culprit(s)

 

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

Myles S. Rose

QUOTE

Hi Myles,

 

I apologize for this delay in replying -- I meanwhile added a connector for external speaker cabinet to the amp and I can see that the hi-freq noise is there only if I use the amp's internal speaker or have the amp sitting on top of the speaker cabinet. Are aging tubes vulnerable to external vibration that may cause this or do you think the cause may be tube clips that vibrate when paying through the amp? Do you still recommend me to push components for troubleshooting or is the presence of external vibration anough to find the problem?

 

Tks

blues&swing

I would need to see this amp on a bench.

[myles_rose]

Originally posted by DARKLAVA:

Hi myles I have a mesa DC5 that seems to go in to boost mode by it self could it be just the knob

or do you think I have big problems?I just bought

the amp so I still have time to take it back.

Take the amp back and have it looked at under warranty.

[sintz_productionshotmail.]

Many people highly recommend your thoughts so I figured I would ask your opinion since your web site pointed here. Below is an excerpt from an email to someone else I am aking for advice from so instead of retyping it I just cut it. I hope this is the right place to ask this.

 

I have a 1984 Carvin X100B on the way thats due Thursday and am preparing to evaluate my situation with it. Currently it has 3 used Mesa 12AX7s (most likely cheaper Sovtek, harsh and hot), and has 4 Sovtek 6L6GBs that were used to replace the original GCs. I believe this was done without re-biasing so they are being pushed to the upper limit as well as dropping the power available. I have 5 12AX7 C9s, Shunguang new production in my box and was thinking of putting one of them in the V1 position and seeing if one has balanced triodes for the V3 phase position. Not sure what will go in V2 yet. Ive been window shopping 6L6GCs and figured I would get all the info I could before buying. Im looking for the original vintage Carvin Xamp sound so Im real slow to move forward since I cant find what NOS tubes to buy for replacement. So basically, Im going to have to trust some opinions and hope for the best.

At any rate, what is your ideas on this situation? Any advice will be helpful if you have the time.

 

Cheers

TC

[exactopposite]

Originally posted by myles111:

Originally posted by exactopposite:

hey myles

 

i got a preamp tube as a part of a trade and i'd like to get some info on it

 

the wrting on the tube says:

 

NATIONAL

6681

MADE IN USA

 

i put it in my amp and it works and sounds great i'm just curious to know more about it. i'd appeciate any info you have on the topic.

This is just a industrial 12AX7 designation. It has no special merit from a high $$$ point and may just be work keeping if you like it sonically.

when i really gave it a listen it had WAY too much treble for my likes even with the treble turned down to about 2. i put it in my v1 slot and an e1 12ax7 in v2. it may have just been a case of 2 bright tubes back to back in the signal, but i went back to my jj 12ax7's. i'll keep them for spare phase inverters i guess.

 

thanx again for the info