That one thing SS-amps will never get you...

Kommerzbassist

Kommerzbassist

Thunderbirdologist
other than tone, obviously...
is that feeling when unpacking your new set of matched and selected premium tubes. Taking them out of their boxes... looking at them in all of their fragile beauty... then putting them in... looking at them while they heat up... biasing them to the maximum recommended current using your lazy a** bias probe tool... that's just where you know that you and your amp belong together.

picture16qv2.jpg

picture18wv6.jpg


Oh... and they sound great, too.
 
Re: That one thing SS-amps will never get you...

So what are they going in? I see a Marshall in your Avatar and your a member of the Fender Fanboy club :)
 
Re: That one thing SS-amps will never get you...

Well SS definitely don't get you the fun of swapping those fine tubes out at a gig, one at a time until the amp works :)

The only thing I enjoy about tubes are the tone :)
 
Re: That one thing SS-amps will never get you...

Kommerzbassist said:
other than tone, obviously...
is that feeling when unpacking your new set of matched and selected premium tubes. Taking them out of their boxes... looking at them in all of their fragile beauty... then putting them in... looking at them while they heat up... biasing them to the maximum recommended current using your lazy a** bias probe tool... that's just where you know that you and your amp belong together.

picture16qv2.jpg

picture18wv6.jpg


Oh... and they sound great, too.
Click to expand...


One question .... "biasing them to the maximum recommended current" ?????

Why would anybody want to do that? Shorter tube life, amp runs hotter and sounds harsh and sterile due to the lack of any crossover notch distortion at low, mid and anything other than max levels.

Another question ... would you want to set the idle speed of a car to 5,000 rpm?
 
Re: That one thing SS-amps will never get you...

kjrocks said:
So what are they going in? I see a Marshall in your Avatar and your a member of the Fender Fanboy club :)
Click to expand...

Yes, they are going into the Marshall, it'S one 7025, three 12AX7s and two EL34s


Myles said:
One question .... "biasing them to the maximum recommended current" ?????

Why would anybody want to do that? Shorter tube life, amp runs hotter and sounds harsh and sterile due to the lack of any crossover notch distortion at low, mid and anything other than max levels.

Another question ... would you want to set the idle speed of a car to 5,000 rpm?
Click to expand...

The answer is simple... DRIIIIIIVE. Dirties up the power section. I use my amp basically full on all the time and adjust the volume mostly by attenuator.
And I haven't ever heard anyone "wanting" cross over distortion before. The main reason i hear people bias their amps cold is to a) save tube life b) clean up the power section... so, I' don't care about either really. Swapping power tubes on a TSL is about 5 minutes.

Regarding the car... dunno... depends on the cams really :firedevil

guitarded said:
Well SS definitely don't get you the fun of swapping those fine tubes out at a gig, one at a time until the amp works :)

The only thing I enjoy about tubes are the tone :)
Click to expand...

Handle your amp well and it'll serve you well... oh and let it cool down before moving... can safe it too.
 
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Re: That one thing SS-amps will never get you...

Kommerzbassist said:
Yes, they are going into the Marshall, it'S one 7025, three 12AX7s and two EL34s




The answer is simple... DRIIIIIIVE. Dirties up the power section. I use my amp basically full on all the time and adjust the volume mostly by attenuator.
And I haven't ever heard anyone "wanting" cross over distortion before. The main reason i hear people bias their amps cold is to a) save tube life b) clean up the power section... so, I' don't care about either really. Swapping power tubes on a TSL is about 5 minutes.

Regarding the car... dunno... depends on the cams really :firedevil



Handle your amp well and it'll serve you well... oh and let it cool down before moving... can safe it too.
Click to expand...

Actually, high idle dissapation will not dirty up the amp it will clean it up.

As far as xover notch distortion, a certain amount of it is part of the classic Marshall tone and biasing it all out make the amp sound thinner and lifeless to my ears.

But in the end it is all personal taste :)

But ... if you want to dirty up the output section just use a short plate 12AX7 phase inverter that breaks down faster ... find one with 0.8-0.9mA of plate current rather than the 1.2mA spec. Or if somebody has a TC tester look for something that is below 1250 TC at 250 volts and 2 volts bias. The plate current is really the better test of this but not all tube testers can measure plate current.
 
Re: That one thing SS-amps will never get you...

Myles said:
Actually, high idle dissapation will not dirty up the amp it will clean it up.

As far as xover notch distortion, a certain amount of it is part of the classic Marshall tone and biasing it all out make the amp sound thinner and lifeless to my ears.

But in the end it is all personal taste :)

But ... if you want to dirty up the output section just use a short plate 12AX7 phase inverter that breaks down faster ... find one with 0.8-0.9mA of plate current rather than the 1.2mA spec. Or if somebody has a TC tester look for something that is below 1250 TC at 250 volts and 2 volts bias. The plate current is really the better test of this but not all tube testers can measure plate current.
Click to expand...

Uhm... what? You say a hotter bias will clean out the sound? Or am I getting you wrong here?

Mine sounds nice and dirty the way it is... and not thin at all... rather the opposite.

I use the TAD 12AX7A-C in my phase inverter... seems to work quite well there. Do you have a favourite tube for that stage, you'd like to reccomend? I'm always open for new stuff.
 
Re: That one thing SS-amps will never get you...

Kommerzbassist said:
Uhm... what? You say a hotter bias will clean out the sound? Or am I getting you wrong here?

Mine sounds nice and dirty the way it is... and not thin at all... rather the opposite.

I use the TAD 12AX7A-C in my phase inverter... seems to work quite well there. Do you have a favourite tube for that stage, you'd like to reccomend? I'm always open for new stuff.
Click to expand...


Yes ... you are hearing my right ... higher idle dissapation generally yields more clean headroom and less distortion.

The 12AX7C's are nice tubes but they vary a LOT. If you are anywhere close to North Hollywood I would be happy to spec the tubes for you and tell you what they are actually doing. It is hard to know where you are going if you don't know where you are at the start and all preamp tubes today are a total crap shoot with the odds stacked very much against the end user.
 
Re: That one thing SS-amps will never get you...

Oops ... just looked at your location ... Vienna, Austria .... a bit far to have you drop by to trace some tubes :)

I like the Sovtek 12AX7LPS or JJ 803S in the PI of these amps but that is personal taste on my part. I make sure they have at least 1.1mA of plate current. 1.2mA is spec but they are all over the place. This is the result of plate current output testing from the most current run from JJ on the 803S

mA output
1.2 - this is the design spec.

Below is what was found as reality. The last thing you want in a PI is one below 1.0mA.
1.1
1.3
1.3
1.1
1.4
1.4
0.9
0.7
0.9
1.1
1.0
1.3
0.6
1.1
1.0
1.2
0.7
0.8
1.6
1.3
0.8
0.6
1.1
0.9
1.5
1.0
1.6
1.2
1.0
1.2
0.7
0.8
1.0
0.7
1.3
0.9
0.9
0.6
0.6
0.8

By the way ... here are the test results on your Chinese TADs. As a side note, when you see plate current above 1.4mA or so that is usually due to very low plate resistance (manufacturing screw up) and the high plate current is offset by very low gain, the tube runs hot, has a short life and works pretty poorly ... and can have crosstalk issues as well:

1.0
2.5
1.2
1.2
0.8
0.8
0.9
1.2
1.0
1.2
0.8
1.0
0.9
1.1
0.9
0.7
0.8
0.8
0.8
0.6
1.6
2.1
1.2
0.7
1.1
0.7
1.2
1.3
0.7
0.6
0.8
1.0
0.9
1.0
0.9
0.9
1.0
1.2
1.2
0.9
0.9
0.9
0.7
0.8
1.0
1.0
1.2
0.9
0.8
1.0
1.6
1.5
1.4
1.5
0.9
0.8
0.7
0.8
1.1
1.2

They are all over the place.

And the TADs as far as mutual conductance which should be 1600 ...

1320
1880
1520
1640
1050
1020
1050
1340
1200
1320
1010
1190
1100
1240
1280
1150
1240
1240
1040
910
1600
1860
1080
590
1310
940
1650
1740
590
560
1300
1450
1350
1470
1370
1440
1260
1500
1550
1370
1540
1600
990
1100
1440
1430
1410
1300
1030
1230
1600
1540
1510
1530
1250
1210
1300
1470
1250
1360
 
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Re: That one thing SS-amps will never get you...

WHAT? Ok... if I turn my tubes bias from lets say 37mA to 42mA, I get more headroom? Not really... mine drives greater than before now.

I order all my my tubes from TAD, so they get selected and tested for low noise, low microphonics, gain etc. anyway, no problems here.
Also their Highgrade 7025 (the RT030, not the RT010) is a great V1 tube if you haven't ever tried it... ;)


Btw did you order them from TAD? If yes, what matching did you order if anything at all.

Edit:

I already tried the Sovtek LPS once and didn't really like it... doesn't have any power. I can't believe these would be a good phase driver since they are VERY low power tubes.
 
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Re: That one thing SS-amps will never get you...

Kommerzbassist said:
WHAT? Ok... if I turn my tubes bias from lets say 37mA to 42mA, I get more headroom? Not really... mine drives greater than before now.

I order all my my tubes from TAD, so they get selected and tested for low noise, low microphonics, gain etc. anyway, no problems here.
Also their Highgrade 7025 (the RT030, not the RT010) is a great V1 tube if you haven't ever tried it... ;)


Btw did you order them from TAD? If yes, what matching did you order if anything at all.
Click to expand...

Low noise and low microphonics is a piece of cake ... just pick low output tubes. That is why the Sovtek 12AX7WA was so widely used in many less pricy Fender amps for so long such as the Hot Rod series.

I posted the results on your TAD 12AX7s by the way in the other post but did not post actual true gain. The spec is for a gain of 100. This is what a batch of TADs did recently.

88.0
72.3
89.4
91.1
80.8
85.0
75.0
83.8
88.9
91.0
84.2
91.5
81.5
82.7
85.3
92.0
95.4
95.4
86.7
91.0
84.2
88.6
77.1
73.8
87.3
85.5
89.2
91.6
73.8
80.0
86.7
90.6
90.0
91.9
91.3
90.0
84.0
88.2
91.2
91.3
85.6
88.9
90.0
84.6
90.0
92.3
82.9
86.7
79.2
82.0
84.2
81.1
91.5
90.0
83.3
86.4
92.9
98.0
78.1
85.0
 
Re: That one thing SS-amps will never get you...

But I don't want low output tubes really. Like I said, I already had Sovtek LPSs and those didn't sound right to me.

Also did you order TAD selected tubes or normal production run tubes from TAD?
Because they have the normal production ones, then there are selected ones and then there are those über matched things.
 
Re: That one thing SS-amps will never get you...

Kommerzbassist said:
But I don't want low output tubes really. Like I said, I already had Sovtek LPSs and those didn't sound right to me.

Also did you order TAD selected tubes or normal production run tubes from TAD?
Because they have the normal production ones, then there are selected ones and then there are those über matched things.
Click to expand...

The phase inverter is not an output tube but each side of it pushes one side of the output section.

You really cannot make a fair judgement on the LPS unless you knew what it was doing ... if you do not know the specs and do not compare apples to apples most folks will generally prefer the tube that is not as far off design spec.

The TADs came from many sources and were specified to be selected to be as close to design spec as possible. I use about a dozen sources in the USA, six in Europe and four in Asia to procure the tubes for test. I found out a long time ago, and it was very true during my six plus years at GT, that if I asked for samples for evaluation they were cherry picked when folks knew they were for me and the production runs then were very far off the evaluation samples.

But ... this is all conjecture at this time. If you want to pay the shipping to send a 1/2 a dozen tubes to me and the return shipping I would be happy to test 6 or so tubes of yours at no charge and give you a detailed printout so you can see for yourself the reality beyond the advertising hype.

One company I consult for has be test and spec every tube that goes into any amp they build. A few doors from them is a large amp company that builds high gain amps. I showed the owner of that company what I did to two of their preamps that each use eight 12AX7s and how measuring things before and after changed things. The results were pretty dramatic to the amp designer / builder and to the player not to mention the folks that were part of this blueprinting exercise.

We can debate these things forever but it might be a lot faster if you tell your vendor that you would like to see the specs they record on a tube where you are paying extra money for this so called premium tube.
 
Re: That one thing SS-amps will never get you...

Sounds really interesting... if I had the money to just ship some tubes to you'd I'd gladly accept this offer.

Btw the JJ 803S you mentioned... isn't that a long plate?
 
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Re: That one thing SS-amps will never get you...

Kommerzbassist said:
Sounds really interesting... if I had the money to just ship some tubes to you'd I'd gladly accept this offer.

Btw the JJ 803S you mentioned... isn't that a long plate?
Click to expand...

Well ... this is not a one time offer ... it is somewhat forever or until I die (which at my age and looking at my past and current lifestyle ... well, on second thought you may want to consider it in the next few weeks ) :eyecrazy:

The JJ 803S is a long plate:

ECC803.jpg
 
Re: That one thing SS-amps will never get you...

So you said I might like a short plate one in the PI, right?
The Sovtek LPS is a long plate aswell if I remember correctly... (haven't used it quite long now)
So which one would you suggest then?
 
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