The Trace Elliot V-type Club!!

[ThisBass]

btw as bias current contributes (directly) to the output current logically this means there should be a question asked if hot biasing really shortens tube livetime.
I think hot biasing might shorten tube live time of tubes IF the amplifier was primarily used in idle mode (no signal present at the input) but, just the moment the amplifier powers a signal then the bias current is used (AC wise) to push power. If there was no bias current present then there was "additional" current neccessary for doing just the same job to run the task.

 

[ThisBass]

For comparison: The SVT is supposed to put out 300W at <3% THD from 20Hz-20kHz and it runs six 6550s. I have seen several bench tests where SVTs are more likely to make about 265W at 5% THD. I believe this is due to the quality of modern tubes. So if your V6 is making 365W at <5% THD I would say that's pretty good. The V6 will easily make 400W, you'll just get more grind (distortion) from the output section.

THD of the SVT amplifier is somewhat "enriched" with some saturation "artifakts" coming off from two diodes which are mainly meant to protect the banks from red glowing the tubes.
I think its not valid to rate amplifiers like an SVT with pure THD numbers, The only serious way to rate an SVT output power (or any amplifier output power) might be to push the amplifier close to the edge of hard clipping along the rail voltage.
Just the same way as GK service manuals tell it how to confirm output power to be up to specs
My SVT amplifier measures about 360 watt, or 380 watt, its hard to read the (conservative) truth at the edge of clipping


The V8 amplifier is a "perfectly" designed amplifier but hits saturation artifacts in a more untypical way. Thus it makes no wonder that some folks may prefer the V6 "musicality" over the V8 performance.

 

[Wasnex]

The V8 amplifier is a "perfectly" designed amplifier but hits saturation artifacts in a more untypical way. Thus it makes no wonder that some folks may prefer the V6 "musicality" over the V8 performance.

I have not heard anything weird in the way the V8 saturates, and my comments were not really related to pushing the amps into saturation.

The V6 is voiced with a bit fuller low end and tends to be tighter and more focused. IMHO, it's rare to find these qualities together, especially in a tube amp.

The V8 is voiced with a bit more open and transparent mids. Some describe the voicing as more aggressive. The lows are a bit leaner and looser.

After a bit of tube rolling, the voicing of my V8 is actually fairly close to the V6, although I have to run the Bass control significantly higher to get the full extended lows.

I should say, I haven't actually heard the V8 with stock TE tubes. It was full of Sovtek 12AX7WAs when I bought it.

 

[Bigbri]

btw as bias current contributes (directly) to the output current logically this means there should be a question asked if hot biasing really shortens tube livetime.
I think hot biasing might shorten tube live time of tubes IF the amplifier was primarily used in idle mode (no signal present at the input) but, just the moment the amplifier powers a signal then the bias current is used (AC wise) to push power. If there was no bias current present then there was "additional" current neccessary for doing just the same job to run the task.

Can you clarify the idle mode part? I leave mine in standby for hours when I am playing throughout the day. Is that bad?

 

[Wasnex]

Can you clarify the idle mode part? I leave mine in standby for hours when I am playing throughout the day. Is that bad?

"Idle" is the amp sitting, unplayed in operate mode.

Basically @ThisBass is arguing that the level of bias does not make a difference in tube life. I don't agree with the analysis. Compare the heat generated by an amp biased at 70% and 90% and you will note a significant temperature difference unless you are playing both amps really loud.

Also, unless the amp is designed to be run at 90% it's probably not going to sound its best biased that hot.

 

[ThisBass]

Can you clarify the idle mode part? I leave mine in standby for hours when I am playing throughout the day. Is that bad?

Yes its bad to leave the amp in standby mode for hours. Too longish standy time can lead to (so called) cathode poisoning which impairs the cathode capability to source electrons.

Personally I use standby only when powering up the amplifier. If I want to break up for about 30 minutes I leave the amp as is in playing mode (idle mode). If I want to break up for longer time (more than about 30 minutes) then I'd switch off the amplifier completely rather than using standby.

Even for cooling down procedure (after the amp was pushed hard on stage) I leave the amplifier in playing mode cause it helps to smooth the cooling down procedure.

 

[ThisBass]

Basically @ThisBass is arguing that the level of bias does not make a difference in tube life. I don't agree with the analysis. Compare the heat generated by an amp biased at 70% and 90% and you will note a significant temperature difference unless you are playing both amps really loud.

Most of all amplifiers are biased in the range of 5..10% at most so leaving the amp in operate mode at about 5% of biasing would not (noticeable) reduce livetime as long as the amplifier does not stay unused in "idle" mode for 24/7.

I think that reasonably expectable break times (in practice) are not suitable to predict a noticable shortening of tube lifetime 5% biasing versus 10% (or even 20%) biasing.
Once the amplifier is used on stage the biasing contributes directly to the output power.
On stage the tubes run very hot, way hotter than leaving the amp in idle mode, this happens independent of either cold or hot biasing

 

[ThisBass]

Most of all amplifiers are biased in the range of 5..10% at most so leaving the amp in operate mode at about 5% of biasing would not (noticeable) reduce livetime as long as the amplifier does not stay unused in "idle" mode for 24/7.

I think that reasonably expectable break times (in practice) are not suitable to predict a noticable shortening of tube lifetime 5% biasing versus 10% (or even 20%) biasing.
Once the amplifier is used on stage the biasing contributes directly to the output power.
On stage the tubes run very hot, way hotter than leaving the amp in idle mode, this happens independent of either cold or hot biasing

For lots of amplifiers it makes no sense (nothing at all) to bias for more than about 30% anyway cause there is (very often) an additional takeover distortion present at highish output level (level greater than about 30%) that can't be compensated with any bias settings.

 

[Wasnex]

Most of all amplifiers are biased in the range of 5..10% at most so leaving the amp in operate mode at about 5% of biasing would not (noticeable) reduce livetime as long as the amplifier does not stay unused in "idle" mode for 24/7.

I think that reasonably expectable break times (in practice) are not suitable to predict a noticable shortening of tube lifetime 5% biasing versus 10% (or even 20%) biasing.
Once the amplifier is used on stage the biasing contributes directly to the output power.
On stage the tubes run very hot, way hotter than leaving the amp in idle mode, this happens independent of either cold or hot biasing

I don't know what you mean by 5% biasing. The V-Type bias procedure is to set the cathode current to 30mA. The actual plate dissipation at idle is probably between 55-58% since the screens draw a small percentage of the electrons that are flowing from the cathode.

 

[Bigbri]

Most of all amplifiers are biased in the range of 5..10% at most so leaving the amp in operate mode at about 5% of biasing would not (noticeable) reduce livetime as long as the amplifier does not stay unused in "idle" mode for 24/7.

I think that reasonably expectable break times (in practice) are not suitable to predict a noticable shortening of tube lifetime 5% biasing versus 10% (or even 20%) biasing.
Once the amplifier is used on stage the biasing contributes directly to the output power.
On stage the tubes run very hot, way hotter than leaving the amp in idle mode, this happens independent of either cold or hot biasing

THD of the SVT amplifier is somewhat "enriched" with some saturation "artifakts" coming off from two diodes which are mainly meant to protect the banks from red glowing the tubes.
I think its not valid to rate amplifiers like an SVT with pure THD numbers, The only serious way to rate an SVT output power (or any amplifier output power) might be to push the amplifier close to the edge of hard clipping along the rail voltage.
Just the same way as GK service manuals tell it how to confirm output power to be up to specs
My SVT amplifier measures about 360 watt, or 380 watt, its hard to read the (conservative) truth at the edge of clipping


The V8 amplifier is a "perfectly" designed amplifier but hits saturation artifacts in a more untypical way. Thus it makes no wonder that some folks may prefer the V6 "musicality" over the V8 performance.

What do you think about bass amps today using numerous 6L6's. I know my b15 uses two but it's low wattage. The 400+ and the Traynor Yba3 uses 12. they do sound good but does that give you anything more than six bigger tubes will?
Mesa came out with the KT88:8. I'm going to guess it was to capitalize on the V8, but i have never seen anyone using one except in a video... and the one at L&m for over 4 grand (3799+tax) has been sitting there for well over a year.

 

[Wasnex]

What do you think about bass amps today using numerous 6L6's. I know my b15 uses two but it's low wattage. The 400+ and the Traynor Yba3 uses 12. they do sound good but does that give you anything more than six bigger tubes will?
Mesa came out with the KT88:8. I'm going to guess it was to capitalize on the V8, but i have never seen anyone using one except in a video... and the one at L&m for over 4 grand (3799+tax) has been sitting there for well over a year.

I believe Mesa designed the 400+ when they felt they could no longer get reliable 6550s. Even now the 6L6 is considered one of the more consistently constructed and robust tubes, but it is not rated for as high of voltage, or capable of producing as much power (tube for tube) as 6550s or KT88s . So to get big power you need a bunch of 6l6s working together. Tone wise, the 6L6 is supposed to be fairly close to the 6550. However, IMHO designer intent has more to do with tone than tube type.

The Mesa 400+ measures about 270W clean. I can't find any bench measurements of the YBA300, but the amp is nominally rated for 300W.

The Trace Elliot V8 is a rare amp. I wouldn't be surprised if the designer of the Mesa Strategy had never heard of it. I believe the Ashdown 427 (also rare) was on the market when the Strategy was designed. It's possible the 427 had some influence on the design of the Strategy, but possibly not in a good way.

The Strategy is a pretty aggressive design that is apparently hard on the tubes. Problems getting good tubes is part of the official explanation of why the amp is being discontinued. Perhaps if the 427 was not on the market, Mesa would have taken a more conservative approach with the Strategy. Ashdown rated the 427 for 427W versus Mesa's rating of 465W for the Strategy.

IMHO the Mesa Prodigy and Strategy were needed because the 400+ had been discontinued for several years. The Strategy seems a natural evolution of the 400+.

 

[Microbass]

Sorry to derail the currrnt topic...

I posted this in the Club a few weeks ago but didn’t get much input. @Wasnex hopefully you could advise?

My V4 MK1 is due a service and potential retube. Sounds fine but the tubes have had around 8 years worth of play time. My question is around the set biasing and the service. I would assume that after this length of time the tubes would potentially need to be re-biased by changing the resistors for each tube. What I’d rather avoid is paying for a service, then buying new tubes within the next year and having to pay for the service again.

I have JJ KT88’s (matched quad) and would stick with them for a second set.

Cheers for any insight!

 

[Wasnex]

Sorry to derail the currrnt topic...

I posted this in the Club a few weeks ago but didn’t get much input. @Wasnex hopefully you could advise?

My V4 MK1 is due a service and potential retube. Sounds fine but the tubes have had around 8 years worth of play time. My question is around the set biasing and the service. I would assume that after this length of time the tubes would potentially need to be re-biased by changing the resistors for each tube. What I’d rather avoid is paying for a service, then buying new tubes within the next year and having to pay for the service again.

I have JJ KT88’s (matched quad) and would stick with them for a second set.

Cheers for any insight!

The V4 has a pair of variable resistors to set bias in each pair of tubes. They are adjusted through the top of the chassis. See the image below for the location.

The tubes do not have bias sense resistors or test points to measure/set the quiescent current. I use bias probes on my V4 and V6 that insert a milliammeter inline between the cathode and ground. There are also probes that insert 1 ohm bias sense resistor between the cathode and ground. A meter is used to measure the voltage drop across the resistor, so you can easily calculate the current. Basically since resistance = 1, voltage = current.

My V4 has 698V on the plates, so be careful and make sure any bias probes you may buy are rated for the voltage. Some of the digital probes are only rated to about 500-550V. You could easily fry an expensive probe with the V4.

If you buy a set of bias probes, it's a good practice to check the bias every year or so. As long as the amp sounds good and makes good power, I would check/reset the bias and continue running the same tubes.

 

[Microbass]

Nice explanation - always wondering what those holes were for!!

 

[Chrome Dome]

Have a question about my Trace Elliot 300H,just got couple weeks ago. I am running it through GK 410SBX,8Ohm,and starting making unusually noise(would have to be there?). I was playing an active bass,and was plugged into the active input. Had gain,close to what is in the picture,and the volume. Bass at 3,mids dimed,and treble at 2. Did it couple times,figured it might be batteries in the bass guitar? So I switched basses,and it didn't do it any more? I went over to the Church this morning where amp is at and ran the bass guitar that was hooked up to it when I heard the distortion,never could get it act up? I changed the batteries,just so I would know they are fresh. Mystery to me! Any comments/suggestions welcome! Just don't appreciate sarcasm,so you will know!

 

[Bigbri]

Sorry to derail the currrnt topic...

I posted this in the Club a few weeks ago but didn’t get much input. @Wasnex hopefully you could advise?

My V4 MK1 is due a service and potential retube. Sounds fine but the tubes have had around 8 years worth of play time. My question is around the set biasing and the service. I would assume that after this length of time the tubes would potentially need to be re-biased by changing the resistors for each tube. What I’d rather avoid is paying for a service, then buying new tubes within the next year and having to pay for the service again.

I have JJ KT88’s (matched quad) and would stick with them for a second set.

Cheers for any insight!

Carefull not to waste money. My 69 Ampeg B15 Has the original ampeg 6SL7 preamp tubes. Sounds killer. Also it has a 30+ year old Mullard 5AR4.
The trace V6 has all original tubes from the 90's. The amps sound amazing I have no reason to change them.
I would say not until you notice a decline in sound.
Keep the old ones for spares. or another amp.
From what i read the best tubes for the V6 are 6 Ruby KT88, Gold Lion in VI , regular priced for the other 3.

 

[Microbass]

Carefull not to waste money. My 69 Ampeg B15 Has the original ampeg 6SL7 preamp tubes. Sounds killer. Also it has a 30+ year old Mullard 5AR4.
The trace V6 has all original tubes from the 90's. The amps sound amazing I have no reason to change them.
I would say not until you notice a decline in sound.
Keep the old ones for spares. or another amp.
From what i read the best tubes for the V6 are 6 Ruby KT88, Gold Lion in VI , regular priced for the other 3.

My concern recently is I decided to pick up a used set of KT88’s when I started gigging again after a hiatus, replaced them in the amp and was distorting at all volumes. The eBay listing said they’d only been used for about 15 hours and came well packed in original boxes and bubble wrap. The amp could do with a service to be on the safe side but at £80/hour I’d rather not have to have 2 serv

Carefull not to waste money. My 69 Ampeg B15 Has the original ampeg 6SL7 preamp tubes. Sounds killer. Also it has a 30+ year old Mullard 5AR4.
The trace V6 has all original tubes from the 90's. The amps sound amazing I have no reason to change them.
I would say not until you notice a decline in sound.
Keep the old ones for spares. or another amp.
From what i read the best tubes for the V6 are 6 Ruby KT88, Gold Lion in VI , regular priced for the other 3.

Quite happy with things I guess. Haven’t been gigging enough to really get a feel for things. Our rehearsal space has become very difficult to control the low end. Last gig I used my rig it sounded great and was very gritty just the way I like it. But then it was grittier than the last time I used that set up. Just don’t want to spend the money on a service and buy new tubes then pay for another service. I’d rather err on the side of caution and re-tube and service at the same time now that I’m playing regualarly again. But as is everything sounds fine so service and replacement is low on my list of things to pay for..

 

[Bigbri]

I have not heard anything weird in the way the V8 saturates, and my comments were not really related to pushing the amps into saturation.

The V6 is voiced with a bit fuller low end and tends to be tighter and more focused. IMHO, it's rare to find these qualities together, especially in a tube amp.

The V8 is voiced with a bit more open and transparent mids. Some describe the voicing as more aggressive. The lows are a bit leaner and looser
My V6 has all original TE tubes. The first thing I noticed was the very loud tight bass. don't need to crank the bass all the way up on the stingray. If anything, drop the pickup a little on the e string to even it out a bit.

After a bit of tube rolling, the voicing of my V8 is actually fairly close to the V6, although I have to run the Bass control significantly higher to get the full extended lows.

I should say, I haven't actually heard the V8 with stock TE tubes. It was full of Sovtek 12AX7WAs when I bought it.

 

[Wasnex]

My concern recently is I decided to pick up a used set of KT88’s when I started gigging again after a hiatus, replaced them in the amp and was distorting at all volumes. The eBay listing said they’d only been used for about 15 hours and came well packed in original boxes and bubble wrap. The amp could do with a service to be on the safe side but at £80/hour I’d rather not have to have 2 serv


Quite happy with things I guess. Haven’t been gigging enough to really get a feel for things. Our rehearsal space has become very difficult to control the low end. Last gig I used my rig it sounded great and was very gritty just the way I like it. But then it was grittier than the last time I used that set up. Just don’t want to spend the money on a service and buy new tubes then pay for another service. I’d rather err on the side of caution and re-tube and service at the same time now that I’m playing regualarly again. But as is everything sounds fine so service and replacement is low on my list of things to pay for..

If you didn't reset the bias when you installed the "new to you" tubes, then it's possible they are simply biased too cold. Even if you replace tubes with another set that is supposed to be an exact match, I think it's a good idea to check the bias. Matching is not an exact science, and the values of the components in your amp shift over time. Normally this amp should be very clean unless you are pushing the gain or volume relatively hard.

 

[Microbass]

If you didn't reset the bias when you installed the "new to you" tubes, then it's possible they are simply biased too cold. Even if you replace tubes with another set that is supposed to be an exact match, I think it's a good idea to check the bias. Matching is not an exact science, and the values of the components in your amp shift over time. Normally this amp should be very clean unless you are pushing the gain or volume relatively hard.

It was another matched set of JJ’s, even from the same shop. But I can get how they maybe the case. I went back to the original JJ’s I had installed years ago. When I do get around to the servicing I’m gunna get the guys to check that set as well. I’ll maybe contact the techs tomorrow and see if they offer a test service.