6C45P tube Rolling

[Lambert]

I have been running Mainline with HD800 for a month. It is an awesome amplifier. I upgraded the components last week, e.g. replacing the 10uF capacitor by Auricap 18uF as per Loquah. It was a positive upgrade,  the overall signature of the amplifier was kept with enhancement in smoothness in both mid and high tones.

I read the thread about tube rolling. Unfortunately, the gold pin Electro-harmonix 6C45Pi is out of stock from all the shops, e.g. Cryoset and Woo. I am thinking the possibilities to replace 6C45P by Western Electric 417A which are still available in China. I saw some people upgrade their WA7 by replacing 6C45Pi by WE417A with a tube adaptor. Is it possible to use? The electrical parameter of 417A is close to 6C45 but still have some difference.  I am a bit of worrying about tube oscillation in Mainline with 417A.

I also find WE437A though it is a bit expensive tube. It is a compatible tube of 6C45P. But it's seemed to me its pins is not 100% the same as 6C45P. WE437A uses a B9D socket while 6C45 uses B9A. Can I still put WE437A into the socket of Mainline or I need to find another tube adaptor?

- Lambert

[Doc B.]

The 437A is much closer to the 6C45pi electrically than the 417A. But it needs a completely different socket. The 417A would be a step backwards sonically.

[Lambert]

Hi Doc,

Thanks for your suggestion. WE437A is an expensive alternatives ($300+ each) and I don't know how much upgrade it can achieve over 6C45P sonically. People said it was a dream tube but I do hesitate about it.

The stock tube of Mainline is quite good indeed. Maybe I should keep on looking for the EH version.

-Lambert

[Doc B.]

IME the difference between the 6C45pi and the WE437A is down to a matter of taste. So I agree that it's a little difficult to justify the price unless one wants an ultimate statement kind of amp. I have not sought out the low noise graded 6C45pis to say if they are any better. 6C45pis are pretty consistently quiet.

[dubiousmike]

Hi Lambert - FYI, it looks like Woo will have more of the EH 6c45pi's come month end if you have your heart set on trying a pair.  (Scroll down on this page: http://wooaudio.com/products/wa7fireflies.html )  I keep flirting with the idea of picking up a pair, but time flies and I don't ever seem inclined to pull the trigger.  I consider it a testament to just how great the mainline is.  I keep concluding that my $100 would be better devoted to a bh dac etc. if there is a second run.

Regarding alternate tubes, I thought you all might find this comment by Doug at ECP pretty interesting.  By way of background, Doug/ECP's L-2 is a derivative of the parafeed design that Doc and crew pioneered many years ago.  Over on changstar (http://www.changstar.com/index.php/topic,1601.40.html), Doug shared the following about his experiments with tube selection in parafeed headamps:

When I was working on the L-2, I built versions using the 6C45, 5842, 6688, 7788, D3a, C3g, E280F, 12HG7/12GN7, 6J9, and one or two others I can't remember ...  7KY6 maybe? Anyhow, I liked the 6C45 the best. To be fair, I used all NOS tubes there, but I have used the Sovteks and can't say I found them to be any different.

None of the others were bad by any means (except that 7KY6), but side by side in the same circuit, the 6C45 had the best performance to my ear. Even accepting the lower gain and output power, I did not find the 5842 to be as good. Perhaps it is a different story into a higher load.

Pete Millett has an interesting writeup on a bunch of these tubes: http://www.pmillett.com/pentodes.htm

[Lambert]

Hi Mike,

Thanks for your advice. As you said, $100 may be not worthwhile (Woo always charges premium over others). I am doing other upgrades recently, e.g. get with a new headphone cable, then Bottleneck Interconnect Kit. SQ is improving. My next step is the Power cord Kit. It is still a long road to go to reach the climax of Mainline. 

- Lmabert

[Doc B.]

Is there really a difference in the 6C45pis out there? They all look the same inside.

[Paul Birkeland]

Is there really a difference in the 6C45pis out there? They all look the same inside.

I heard a rumor that the new EH's did away with the exotically plating on the grids. If this is true, it would be a pretty big negative that wouldn't be outweighed by having gold pins.

[swich401]

Is there really a difference in the 6C45pis out there? They all look the same inside.

Comparison of the stock tubes (Reflector) with a set of Sovtek tubes (Rebranded reflector) - No physical difference apparent.

Comparison of the stock and sovtek tubes with Electro Harmonix gold - The EH has a smaller halo getter and no wire leading from the central element to the post holding up the halo getter. Not sure about plating on the grids tho, hard to tell by eye.

[swich401]

I found this link late last night: http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Trioden/Russische_Leistungstrioden/Russische_Leistungstrioden.htm

See near the bottom of the page for some comparisons between the Reflector, Sovtek and EH GoldPin tubes.

The EH 6C45's that I currently have (purchased from Woo Audio) are different from all the 6C45 tubes shown in that link. Mine are almost identical to the Reflector's, but have a smaller circular disk getter and no wire leading from the central element to the post holding up the getter.

[Lambert]

Some people in other forums said Sovtek and EH were identical (both are brand names of NewSensor now). The only difference is the gold pins and hence they do not differ much sonically. I haven't listened to EH version. I cannot verify. 

If I do buy EH, I prefer Cryoset to Woo, they are much cheaper. Do anyone try both EH and stock Reflector with Mainline and give their opinion?

-Lambert

[swich401]

I recently did some tube rolling (albeit slow tube rolling, seeing as I had to re-adjust the bias each time I swapped tubes) with the Sovtek, Reflector and EH tubes that I have.

To be honest, not too much difference between the three of them, but here are some slight things I THINK I may be hearing when comparing the 6C45 tubes I have in my possession:

Sovtek - Most grainy treble out of the three (but this could potentially be due to these tubes having the least run-time). I did burn them in for over 100 hours when I got them. Seems to be more extended up top (treble) than the Reflector tubes, but again this may be due to the slightly less smooth treble I'm hearing with these tubes.

Reflector - Most mid-centric sound out of the three tubes. Smooth treble. My preferred tubes to use with HD800's listening to most of my music collection except for really well recorded classical, instrumental, etc.

Electro-Harmonix - Less mids than the Reflector tubes. More extended up top and down below. Treble just as smooth as Reflector. I like using these tubes when listening to the best recording in my collection, especially for classical music where the extension up top and down below is a bonus.


If I had to stick to just one brand/make of 6C45's to keep in my Mainline long-term it would be the Reflectors for sure.


Of course, take this with a grain of salt, it's only an opinion 

[Lambert]

Thanks for your advice.

I like the sound of Reflector (the stock tube of Mainline). If I get a good deal of EH, I'll buy a pair.

-Lambert

[NightFlight]

Is the 6H30 a drop in?

[JamieMcC]

Mainline  Tube Rolling

(https://www.head-fi.org/content/type/61/id/1576004/width/200/height/400/flags/LL)

I couldn't resist trying the 6S15P in the Mainline and the results have been interesting there is certainly some noticeable differences to the 6S45P-E Gold Pins I have been running for the last 9 months.

So a few observations in comparison to the 6S45P-E Gold Pins, bearing in mind I only have been using them for a couple of days now.

The general sound of the 6S15P is more crystalline in nature than 6S45P-E which I think sounds the more organic or analogue of the two. You could say the 6S15P has a touch of solid state about it compared to the 6S45P-E .

The 6S15P without doubt delivers a higher level or resolution its revealing lots of new little details and I have found myself several times now lifting my cans off my head to check/listen for sounds in the house which they were actually new details revealed on the headphones. 

Treble comes across as crisper and cleaner with more headroom it is a slightly more etched treble. Listening to a orchestral piece recorded in a large cathedral the music feels like it’s soaring up into the high vaults of the cathedral ceiling and the shimmer on cymbals impressed.

Mids feel a fraction less intimate and involving emotionally compared to the 6S45P-E however this is a area where the sense of presence and density of tone has continued to improve with run time.

Bass seems tauter with a fraction more punch and a noticeable increase in its texturing.

Depending on what genres your preferences are it’s got to be good to be able to roll tubes and still tweak the Mainline just a little to suit personal tastes.

The 6S45P is my favourite for folk/bluegrass or small ensemble acoustic music and feel it does a better job of delivering textual clues with a more natural and life like tone of solo instruments and vocals.  While the 6S15P digs up increased level of details of the wetness and hollowness of a note blown through a woodwind instrument the 6S45P is a fraction less resolving but to my mind delivers the more convincing tone of the note and woody-ness texture of the instrument through which it was made.

The 6S15P comes into its own with more complex music and orchestral where its separation and air help with the portrayal of scale and crescendo with the higher resolution digging out some nice little instrumental nuances from amongst the orchestra.  Before I turned in for the night I wanted to check out a couple of tracks on Florence and the Machine's Ceremonials album which is a reasonably busy album and ended up listing to the whole thing finally turning in at 2am…

Cheers
Jamie