Different Tubes In A Tube Tech CL1B

[World Studios]

Hi Folks!

This is my virgin thread. I think you will like it, but lease be gentle with me ;-)

I have prepared a small test for you of how different tubes change the sound of my fave compressor, the CL1b.

First off download the 50 meg file from my server here:

http://www.worldstudios.se/TubeTechCL1bTubeTest.zip

The files are named properly and include the following:

1 Reference file, no compression.
2 Stock Tubes, Russian EH, that came with mine bought new recently
3 The tube from my Manley Ref C mic! (I only exchanged the input 12AX7 tube)
4 Vintage Telefunken tube (I only exchanged the input 12AX7 tube)
5 Mullard 4001 and 4004 tubes - the expensive shit! from my friend Stellan Colt's CL1b
6 Siemens Tubes from my friend Per Davidsson's CL1b

There are obvious differences in the general sound, but be sure to listen carefully to how well they handle the low frequencies. The cheaper tubes are not as fast and responsive there and blur the sound. The audio has been compressed a bit to much, to show us how the tubes behave under pressure. Some of the audio has been taken from the excellent NU47 vocal and guitar 8 mic shootout. Used by kind permission from gatiii. Since I mostly use it for vocals and guitar, the bulk of the audio is just that, but there is a pop mix at the end so you can hear how they handle complex audio as well. If you want to compare it to your own CL1b or any other compressor, for that matter, the settings were:

Gain +5 Ratio 12 o' clock Threshold -10

Attack 11 o' clock Release 12 o' clock Manual

Unity gain in and out. My samples are on Apogee AD/DA16x, Per and Stellan have other convertors. You do the math! :-)

I have tried some of these tubes in My Manley Ref C mic and the general sound will change the same way. Enjoy!

[gatiii]

Hey Johan:

Thanks for taking the time to post this test. It should be interesting to see the results.

Regards,
Glenn Tabor

www.gat3.com

[kittonian]

Just out of curiosity, which specific tube was the "vintage Telefunken tube" you used? How old was it, was it NOS, had this tube been used before or is this the first time, etc.?

[World Studios]

I am no tube expert. Bowie sold it to me and might be able to shed some more light on this. It was ribbed and re-branded Fischer, I believe... Vintage, for sure, not newly made. Lets wait 'til Bowie awakens, shall we? :-)

[BOWIE]

Originally Posted by World Studios

I am no tube expert. Bowie sold it to me and might be able to shed some more light on this. It was ribbed and re-branded Fischer, I believe... Vintage, for sure, not newly made. Lets wait 'til Bowie awakens, shall we? :-)

So, I've finally awoken. (~stretch~, :yawn
Johan's tube is a ribbed/ladder plate Telefunken ECC83/12AX7, Fisher pull testing far above new/nominal levels but probably burnt-in sufficiently as it has that characteristic silkiness of a Telefunken in its prime. I think it was 1963 manufacture though the date really doesn't matter w/ Telefunken like it does with other manufacturer's tubes.

[BOWIE]

Originally Posted by World Studios

there is a pop mix at the end so you can hear how they handle complex audio as well.

For me, this portion is the most telling. You can really hear a difference in high frequency response and texture along with bass extention and the overall tightness of the low end. The midrange detail is also exposed.

[wildhoney]

Originally Posted by World Studios

1 Reference file, no compression.
2 Stock Tubes, Russian EH, that came with mine bought new recently
3 The tube from my Manley Ref C mic! (I only exchanged the input 12AX7 tube)
4 Vintage Telefunken tube (I only exchanged the input 12AX7 tube)
5 Mullard 4001 and 4004 tubes - the expensive shit! from my friend Stellan Colt's CL1b
6 Siemens Tubes from my friend Per Davidsson's CL1b

I was under the impression that the input tube in a CL1B is a 12au7/ECC82 and the Output tube is a 12ax7/ECC83. (Input in the middle of the circuit board, output at the left side of the board when facing the front of the unit). Am I mistaken in this?

[space2012]

Originally Posted by World Studios

Hi ...
small test ... different tubes change the sound of my CL1b.
... the 50 meg file include the following:

1 Reference file, no compression.

5 Mullard 4001 and 4004 tubes - the expensive shit! from my friend Stellan Colt's CL1b
...
excellent NU47 vocal and guitar 8 mic shootout.
...
If you want to compare it to your own CL1b or any other compressor, for that matter, the settings were:

Gain +5 Ratio 12 o' clock Threshold -10

Attack 11 o' clock Release 12 o' clock Manual

Unity gain in and out. ... Apogee AD/DA16x, Per and Stellan have other convertors. ...
I have tried some of these tubes in My Manley Ref C mic and the general sound will change the same way. Enjoy!

do you have a link to the other test?

anyway,
here the mullar4004/4001 tubes sound transparent mids & highs but added warm, compressed dynamics with a touch of harmonic magic in the highs.
verry surpriced/dissapointed with the telefunken

the stock russian tubes are sovtek ?

[BOWIE]

Originally Posted by wildhoney

I was under the impression that the input tube in a CL1B is a 12au7/ECC82 and the Output tube is a 12ax7/ECC83. (Input in the middle of the circuit board, output at the left side of the board when facing the front of the unit). Am I mistaken in this?

I've read the opposite. There was a thread here somewhere. I have not inspected the PCB myself (nor being able to find any contact info for Tube Tech tech-support) though. Traditionally, a higher gain tube, like a 12AX7, will be on the input.

Originally Posted by space2012

here the mullar4004/4001 tubes sound transparent mids & highs but added warm, compressed dynamics with a touch of harmonic magic in the highs.
verry surpriced/dissapointed with the telefunken

I think the Mullards would be perfect on some sources because of the "harmonic magic" () but I didn't care for the way they got chopped off in the low-end and britle in the treble at the last portion of the clip. To my ears, the Telefunklen dominated in tight low-end extention along with the airy and detailed highs. They are so different from each other that it's just a matter of taste and style.
I was surprised that the Siemens didn't hang with the Tele in the treble or bass. Still offered a lot of detail though.
Hopefully Johan will give an update next week using an Amperex. That's a very versatile, dynamic tube that has midrange richness w/o losing too much low or high end.

[ThomasWho]

Thanks for posting the files!

1 question for all you who own 2x , how are they on the 2Bus? I see no reason why they couldn`t add a little tube color in a nice way ?

Thomas

[World Studios]

Originally Posted by wildhoney

I was under the impression that the input tube in a CL1B is a 12au7/ECC82 and the Output tube is a 12ax7/ECC83. (Input in the middle of the circuit board, output at the left side of the board when facing the front of the unit). Am I mistaken in this?

Hi!

I think you have that backwards, friend. I replaced the one in the middle, 'cause it said 12AX7 and I am pretty sure it says "gain" on the circuit board next to the leftmost tube, placed directly behind the makeup gain knob.

Cheers,

[World Studios]

Originally Posted by space2012

do you have a link to the other test?

anyway,
here the mullar4004/4001 tubes sound transparent mids & highs but added warm, compressed dynamics with a touch of harmonic magic in the highs.
verry surpriced/dissapointed with the telefunken

the stock russian tubes are sovtek ?

Well different folks listen to different strokes (of the paintbrush)... I agree the mids of the Mullads are magical, but where did the low end go? I, for one, want the output to stay true to the input in most cases and the tube with the highest fidelity is without a doubt the Telefunken.

I believe the 12AU7 output tube is Sovtek, but the input one is Electro Harmonix Russia

[futur2]

interesting. i like siemens and telefunken. mullard was not my cup of tea. but definitely lets me think about changing tubes in some of my gear...

[World Studios]

Go right ahead! You can expect the same improvements in most any tube gear. If you don't feel like kissing a few frogs to find your prince, get the tubes from Bowie. He does the legwork and he does it well. From what I hear, he lives way out in the Arizona desert, because it is so darned quiet there. :-D

[futur2]

Originally Posted by World Studios

From what I hear, he lives way out in the Arizona desert, because it is so darned quiet there. :-D

might consider your advice thanks!

[Matt Syson]

Hi
On all Tube-Tech units an ECC82 is the output valve. This is preceeded by an ECC83 (or graded version).
On the units that use a valve as the VCA it will be either an ECC81 or ECC82. They are NOT interchangeable although some units have been modified to use 'the other type' as it is difficult to get stock of decently 'balanced' valves and the change eases the requirements.
In ALL cases the balance adjustments must be remade to suit the new valve so simply stuffing a new valve in will 'mess' it up completely, even swapping the valves for channel 1 and 2.
Finding valves which are suitable as VCAs is not easy as they must have well matched 'halves' low noise, low microphony and have similar 'law' to the one used for the other channel.
Matt S

[World Studios]

Hi, Matt!

We are talking about the CL1B here, and as you know it does not have a valve for the VCA, plus it is mono, but I appreciate your input on VCA valves. Good to know. I just replaced the input tube on my Tube-Tech with another one of the same type. I guess you should recalibrate and all, but the output measures the same for two of the tubes in this test (from measuring the audio file) and one was 0.1 db louder. I can live with that...

Cheers,

[Matt Syson]

Hi
Thanks, I don't keep all the TubeTech variations in my head so was not 100 percent sure that it was a VCA valve version or not.
In the case of the CL1b there is only really the 'gain' pot on the main board to be adjusted if you replace either of the valves and as you noted if they are basically in good condition the change is small.
Matt S

[wildhoney]

Not to be redundant here, but can someone just finally clarify for me the proper tube array for the CL 1B? I just opened mine up and V1 (far left of the circuit board when facing the unit) is a 12ax7, V2 (center of the circuit board) is a 12au7. If this is correct, does this mean that V1 is the input tube, and V2 is the output tube? Sorry to revisit this, but would love to know once and for all since Tube-Tech's net support is pretty much non-existent.
Thanks!

[Matt Syson]

Hi
V1 is the input and as printed on the board should be an ECC83 whose direct equivalents would include 12AX7 and 7025. The 7025 has a spiral wound heater to reduce 'hum' but as it is fed with clean DC in any TubeTech unit this is academic.
V2 should be an ECC82 or equivalent with a lower mu but higher maximum cathode current capability compared to the ECC83.
Fitting the valves 'swapped over' would produce a very sick unit hardly capable of driving any real load. It would still do something though.
The TubeTech dealership in your country should be taking up any service questions you may have, they get the money for selling them.
Best regards
Matt S

[wildhoney]

Originally Posted by matt syson

hi
v1 is the input and as printed on the board should be an ecc83 whose direct equivalents would include 12ax7 and 7025. The 7025 has a spiral wound heater to reduce 'hum' but as it is fed with clean dc in any tubetech unit this is academic.
V2 should be an ecc82 or equivalent with a lower mu but higher maximum cathode current capability compared to the ecc83.
Fitting the valves 'swapped over' would produce a very sick unit hardly capable of driving any real load. It would still do something though.
The tubetech dealership in your country should be taking up any service questions you may have, they get the money for selling them.
Best regards
matt s

thank you!

[BOWIE]

Originally Posted by wildhoney

Not to be redundant here, but can someone just finally clarify for me the proper tube array for the CL 1B? I just opened mine up and V1 (far left of the circuit board when facing the unit) is a 12ax7, V2 (center of the circuit board) is a 12au7. If this is correct, does this mean that V1 is the input tube, and V2 is the output tube? Sorry to revisit this, but would love to know once and for all since Tube-Tech's net support is pretty much non-existent.
Thanks!

Wow, that's crazy. I'm not sure how that ended up happening but you'll find that your CL1B sounds very different once you get the tubes corrected! It should sound much fatter and fuller in the midrange along with having a better noise floor. Good think you asked.

[wildhoney]

Originally Posted by BOWIE

Wow, that's crazy. I'm not sure how that ended up happening but you'll find that your CL1B sounds very different once you get the tubes corrected! It should sound much fatter and fuller in the midrange along with having a better noise floor. Good think you asked.

The tubes were correct in my unit, as I described in earlier post and confirmed by Matt Syson above. I would have been shocked if they were wrong since it's been almost impossible to make this thing sound bad on a vocal. Main reason I was asking was b/c I had one of the tubes fail (the 12ax7 in V1) and I wasn't sure if that meant i was replacing the input or the output.

[BOWIE]

Originally Posted by wildhoney

The tubes were correct in my unit, as I described in earlier post and confirmed by Matt Syson above. I would have been shocked if they were wrong since it's been almost impossible to make this thing sound bad on a vocal. Main reason I was asking was b/c I had one of the tubes fail (the 12ax7 in V1) and I wasn't sure if that meant i was replacing the input or the output.

Oh, I see. I was under the impression that yours were mixed up.



Has anyone had a chance to take that dry file that Johan posted and run it through their CL 1B w/ upgraded tubes?

[James Lugo]

Is there a tech in LA that can come to studio and change out the tubes?

p.s. thanks for doing this man.

[World Studios]

Señor Lugo! You are welcome! You don't need a tech. You unscrew the 3 phillips screws on the top, take the lid off, pull out the two stock tubes and put the two ones of your choice back in. If you can connect a tube mic to its powersupply, or an xlr cable to a mic - you can do this yourself. It will take you 5 minutes tops. What's the minimum charge for a tech? The way I see it, you do it yourself and get the tubes for free... $weet deal. Only thing that could go wrong is you switch the 12AX7 and 12AU7, but if you do them one at a time, put your glasses on and read what it says in big letters on the tube, you can not go wrong. I did it three times last week ;-)

[James Lugo]

So what are the model tubes I need?

Sorry for the confusion, I'm just not a tech dude at all and these type of threads lose me. How many and what exact models?


Thanks

[World Studios]

1 of 12AX7 and 1 of 12AU7

Which make did you prefer out of the ones in this test? Please vote!

Ask Bowie for help. This is his field...

[James Lugo]

Been on the phone with some CL1B tech dudes trying to get their take on it.

I'm not sure which ones, the Teles and Mullards stand out so far.

[Matt Syson]

Hi
Not to put a dampener on proceedings but be aware that there are voltages inside which CAN KILL. Work on it with someone else present so they can dig the hole for you.
Since you would typically be holding the unit down with one hand and 'fiddling about' with the other inside the unit a classic case for a shock from left to right hand ACROSS THE HEART.
If the unit has been powered up, leave it about 5 minutes for the high voltage to bleed away, for one thing the ECC82 will burn your fingers if you grab it too soon!
There is not a lot that is at a high voltage and the most likely to be touched are the power resistors to the right side (from front), the power transistors in the regulator and the fuseholders.
Changing valves will alter the overal gain but this is simply gain not any other response so you can ckeck this by measuring what is going in and what comes out.
Unless you are replacing seriously 'stuffed' valves the gain variation between them is likely to be around 1dB max.
Have fun but take care.
Matt S