Tube Rolling w/Crack

[Zarno]

Hello You all !!!


Definitely very happy to be able to join this group after years and years of readings but most of all being able to own "the beast"!!!!

As a Euro listener it wasn't that easy to get it( 10 years ....), but now i proudly have a crack with SB and lots of good mods. Of course my cans are HD 650 with an Alo green cable (possibility of switching the terminations) .i did add an high End power cable as a Audiquest NRG 5 and Qued silver RCA cable.
I received my unit with 6080 WC Phillips EGC and GE 12 AU7, but after few first listening sessions, i became very disappointed because of the lack of .........everything  . No magical appears ......flat; dull; mushy , thin , so i confess i was devastated!!!
So i managed to start tube replacement or rolling and had the chance ( i primarily thought..) to find Nos Telefunken set for input and outpout tubes .
The sound was completely different but very harsh and hard to listen to..............very mid centric even with a bettered sound stage , but with no life ....lean sound with nice details and vocals but no foot tapping; not engaging after ( to 10 minutes i stated to get tired of the sound !!!!    wow what did i miss?
so i tried to split the combos  and made a session with Telefunken 12 Au7 and Phillips 6080 , things calm down a bit , but lack of impact and seems a little bit foggy.......!

So i'm asking you ; the "gods of the Crack" to help me out a bit and try to find the right combos with all the experimentations you all guys made the last ten or fifteen years !!!!!!
Knowing i had the chance to find a RARE set of Nib Nos Telefunken (west germany from the 50's) found with luck by one of my friend in a closet in the garage (  ) ; owned by his grand pa ; i went thru tons of pages on different forums, but cant find the top pairing with these 2;
i really like the 12au 7 precision and details and would like to try to find an outpout tube that can handle it ;something maybe  more organic, rugged  ; but with a good impact on bass slam, speed  and as refined ........ i guess i m a fool
or try to find a perfect matching input tube to the telefunken 6080 but as it is a rare and sough after tube , i couldn't find anyone or read anything on some one who tried a special combo on our beloved Crack .

Thank you so much for your help and support and hope it's not a too big pain in the a...to understand  my poor English !!!!
thanks to the community .
Zarno

[Paul Birkeland]

I would recommend reheating all of the solder joints in the amp before you go much further.  What you're describing is how I would describe an amp with a few cold joints.  The music will still come out, but it certainly doesn't sound right!

[Deluk]

The standard HD650 cable is fine and makes a good standard reference. I bought my HD600 used and it came with a decidedly expensive East European cable as an extra. It has loads of definition but is balanced very much towards the high frequencies. Reading that the 650 cable was a good value upgrade from the 600 one I bought one and have been pleased with the result. Your green cable might be giving you a similar altered frequency result to my fancy one so best for you to use the 650 one for tube rolling at the moment IMO. Mine came with a RCA 6080 which I like and I'm using it with a 4003 which I just happened to have. A good combo for me. I also have 2 versions of the 6AS7 that sound "OK" but both have issues, the Sylvania one is ultra microphonic and the other one Brimar(?) tends to "sing" a bit one channel. You can only hear that when there is no input signal so not that significant until you wear the cans for a while with nothing playing. Food for thought?
PB's comment posted while I was writing this. Good advice.

[Deke609]

... i proudly have a crack with SB and lots of good mods.

Hi Zarno - a couple of questions:

(1) Did you build it yourself or buy it already built?

(2) What mods, in addition to the SB, does your Crack have?

cheers, Derek

[Tom-s]

@ Zarno.

Follow PB's advice first. Even with GE's it should sound right. Or these were bad tubes, could be.

 Finding real Telefunken 6080's will be extremely difficult. It is a very popular fake, be very careful. And the bass is lacking i.m.e.. I'd put my money on a GEC 6080 instead (found for +-50€ from the UK).

Here's a post of myself on another forum:

Tonight i've had a first few hours with a Telefunken 6080WA output tube. A tube i previously thought off as non-existent with only fakes on the market.
Bought it by chance, as is. Tested it >100% NOS, lucky me!
Telefunken only produced +- 27.000 6080's and 9.000 6080WA's (i have a 1965 6080WA).
For comparison, the rare and wanted ECC803s almost 150.000 pcs. The 6080WA is as rare as the EC8020.
The cheap ones found on ebay and other websites are mostly Telefunken faked GE / RCA / Thomson (France) tubes (the last ones sound good aswel!).
Read about the fakes here https://jacmusic.com/nos/images/Fakes/

Never read about these on this forum nor found a review. So it was a gamble for me.
How does it sound? Clear, open, detailed. It's just turning up the typical Telefunken sound another notch.
It's a tube to look out for! Definitely! And you can easily identify them by build (see Jac).
The tubes.rs ones are the real ones.

A word on the Telefunken 6080WA sound. After a few evenings of listening i can't get it to sound optimal. It has the typical Telefunken sound but lacks in lower end (extension).
This makes it an awesome tube, but only for those wanting to make their system as detailed as possible. I prefer the Bendix/GEC type 6080 sound.
A picture on the night stand, with a Heerlen E80CC to fatten up the sound without losing quality.https://ep1.pinkbike.org/p5pb17821429/p5pb17821429.jpg

For output tubes, my recommendation would be a Svetlana 6H13C with your Telefunken driver (nice coke bottle).
You can find these on E.ay.

Edit: O, you own Telefunken 6080's wow! Want to trade for a few driver tubes?
But my advice on that one would be, DONT!

[Paul Birkeland]

The Thompson/RT French made 6080s have been sitting well with me lately, maybe even more than the 5998.

[Zarno]

wow ......thank you so much guys for your explanations................ i m on my bottom!!!

i ll come to you in few hours with pics and writings..........as usual some very good but also bad facts.

i wish you all a good wake up ....

[Zarno]

I would recommend reheating all of the solder joints in the amp before you go much further.  What you're describing is how I would describe an amp with a few cold joints.  The music will still come out, but it certainly doesn't sound right!

thank you Paul for your highlight.........!!! i didn't know this was possible . is there any particular one i should try first ?...or for sure have to re-do all of them
i will later post few pics of the bottom as i will also do for the TFK tubes.

[Zarno]

The standard HD650 cable is fine and makes a good standard reference. I bought my HD600 used and it came with a decidedly expensive East European cable as an extra. It has loads of definition but is balanced very much towards the high frequencies. Reading that the 650 cable was a good value upgrade from the 600 one I bought one and have been pleased with the result. Your green cable might be giving you a similar altered frequency result to my fancy one so best for you to use the 650 one for tube rolling at the moment IMO. Mine came with a RCA 6080 which I like and I'm using it with a 4003 which I just happened to have. A good combo for me. I also have 2 versions of the 6AS7 that sound "OK" but both have issues, the Sylvania one is ultra microphonic and the other one Brimar(?) tends to "sing" a bit one channel. You can only hear that when there is no input signal so not that significant until you wear the cans for a while with nothing playing. Food for thought?
PB's comment posted while I was writing this. Good advice.

Hello Deluk !

sorry i forgot to mention that for all my initial tube test , i use the HD 650 with the stock cable and regarding this would you be kind to tell me if there is a way to correctly set it back to the headphones (only one way to insert the plug??? not easy to say that in french translation  =Keyed?) i mean when you look at the outside of the HD 650 , are you able to see the letters R or L on the plugs ? or it should be on the ears side ?

I say that because since i install the stock cable back ; i hear a lot of scratches and weir noises when i move the head 

[Zarno]

Hi Zarno - a couple of questions:

(1) Did you build it yourself or buy it already built?

(2) What mods, in addition to the SB, does your Crack have?

cheers, Derek

thanks Deke609 for the questions !

Unfortunately i didn 't build the Crack myself as i was living in Indonesia and just got back to Paris , and from indonesia the Bottlehead Crack site and forum was "ban" with my IP , so i was note able to make any orders...... so i had to do differently and finally found a young Canadian student in electronics who proposed himself to buy it for me and also build as he already did for 2 units.
So i had a chance to increase and choose the level of mods :

I have teflon sockets with gold pins
aluminium volume knob with step up attenuator
rhodium rca sockets and ......
uhhh forgot the rest ! but not sure at all any caps ?   while i did order it ; i move out of indonesia and got my computer stolen with all writings concerning internal modifications...... i m ashamed not to answer more precisely.....and of course the guy is not answering anymore .......

and i have to be honest , its out of my reach to build such a thing , ironing for me was 35 years ago !!!!!

[Zarno]

@ Zarno.

Follow PB's advice first. Even with GE's it should sound right. Or these were bad tubes, could be.

 Finding real Telefunken 6080's will be extremely difficult. It is a very popular fake, be very careful. And the bass is lacking i.m.e.. I'd put my money on a GEC 6080 instead (found for +-50€ from the UK).

Here's a post of myself on another forum:


For output tubes, my recommendation would be a Svetlana 6H13C with your Telefunken driver (nice coke bottle).
You can find these on E.ay.

Edit: O, you own Telefunken 6080's wow! Want to trade for a few driver tubes?
But my advice on that one would be, DONT!

Hello Tom s
 i confess you scared me so much this morning while reading the incredible post you enclosed ; i had to quit eating my breakfast !!! lol
but i have to say ........i might have an incredible luck for these tubes  i will enclosed fw pictures i have made this am and will wait for your confirmation but reading all the warnings and the ways to make detection of a fake , i think i can dance and scream loud saying i have a true and original almost new Telefunken 6080 

same for the 12 AU7 ..........there s nothing on it at all except strange paint on the very tip .............................AND a diamond with positive edges  but i might be not very good with macro pictures and need to clarify this !!!!
thank you so much for the quality of your article   and sorry if its not allowed here  , i won 't do it no more.... but Fuck the fakers!!!

[Deke609]

Hi Zarno -

Another suggestion and a thought.

Suggestion: can you take some clear photos of the wiring and post them on the forum?

Thought: some of what you are hearing (and not liking) might be explained if you had the electrolytic output capacitors replaced with film capacitors. Film caps can take a while to "burn in". In my various experiments with film caps, I've found that at first listen the treble can be a bit harsh and the bass is often muted and mushy. With extended use, the treble is usually the first to get better, with punchy and clear bass being the last thing develop (taking as long as 100 hrs with some of my caps).  The capacitance value of the caps can also affect the sound - for example, if you replaced the output caps with much smaller value film caps.

cheers, Derek

[Zarno]

Derek

yes for sure !!!!! i m about to !!! and my crack doesnt even have 20 hours i guess !!!

[Zarno]

@ Paul

yes it should be easy for me to find such tube !!!! heard a lot about it lately ....... i m not so far from the old factory!!!!! Thomson or La radiotechnique is the same so what kind of driver tube do you use for this nice sounding combo??

but people are crazy here about since a very little time ; can t find one for less than 60 euros !!!
same as Tom's says ....i ve been looking for a GEC put people are asking me 100 bucks ,grrrr

one of my friend can sell me an RCA 6AS7 G for 40 and a Mullard uk for 100 ??

[Paul Birkeland]

is there any particular one i should try first ?...or for sure have to re-do all of them

There aren't that many solder joints in the amp.  I can reheat and reflow all the joints in a Crack in about ten minutes.