Bottlehead Forum
Bottlehead Kits => Mainline => Topic started by: Lambert on March 15, 2015, 08:42:42 PM
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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
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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.
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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
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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.
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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
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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
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Is there really a difference in the 6C45pis out there? They all look the same inside.
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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.
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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.
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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.
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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
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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 :P
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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
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Is the 6H30 a drop in?
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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
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Is the 6H30 a drop in?
Nope.
https://www.newsensor.com/pdf/sovtek/6c45pi-sovtek.pdf
https://www.newsensor.com/pdf/sovtek/6h30pi-sovtek.pdf
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...
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.
Cheers
Jamie
I popped the 6S15P pair that I got and some time flew by. Umn... almost three years now? I did re-bias them twice and due to a busy work life, likely only able to put around 400 hrs listening time on them. I found myself listening to the Mainline quite wanting the last few months - ready to sell.
I popped in my EH 6C45pi - re-biased them nearly to the limits of the trim pots since they were outputting 180V/190V (should be 145V)
I suspect the 6S15P were on their way out? While not as wide, once warmed up, these EH are bold, spacious and visceral. Falling in love with this amp all over again...
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Hey Jamie and crew...sitting here listeing with T1's and my Crack...and am amazed at how good this combo is....
Jamie as u know I am looking towards getting a Mainline or abrand X but so far because I like building stuff and like the BH sound of the crack its making more and more sense to go the Mainline route..
The availability of tubes and whats inside them, ie the magic exotic metals that Paul mentions etc....and not really knowing what the tube manufacturers are really making or plating the internal elements with palladium etc is a concern.
That said if the tubes Doc sends in the Mainline kits produce this "great" BH sound I could care less....lol.
Also I would like to know if BH sells or would sell extra tubes to ensure we get the same type that was shipped and at what cost?
I would order one set when ordering the kit, not wanting to "hog" or "horde" tubes, just to have one backup set just in case and the same as the originals as best possible.
Alex
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AFAIK all 6C45pis are the same.
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I found a supply of 6c45pi's, Reflektor type for approx $17 each....not bad considering most are running $30 each...and higher.
Waiting on the kit to ship, getting excited and cant wait to solder once again.
Thinking of using tung oil on the wood and clear coat afterwords...
Alex
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AFAIK all 6C45pis are the same.
That's the theory. Its all subjective. I think perhaps the best sounding tubes are mystery tubes where all the labelling has been scraped away.
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Hopefully it's not all subjective, as then we could all be just as happy buying a pile of $8 MP3 players from an electronics liquidator website and sorting through to find the one that is the most organically liquid and convincingly detailed while having air, presence, bass punch, midrange lushness and PRAT like a fine vintage Malbec, Merino wool running shoes or the smell of wet hunting dogs by the fire.
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Hopefully it's not all subjective, as then we could all be just as happy buying a pile of $8 MP3 players from an electronics liquidator website and sorting through to find the one that is the most....
I'm fairly sure that's described in Dante's Inferno. Likely there's a guy with a pile of them doing just that, somewhere in the shadows of the 9th circle.
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Likely there's a guy with a pile of them doing just that, somewhere in the shadows of the 9th circle.
Or in a dorm room, with his Hipstreet Titan open to an 8000 page MP3 player comparison thread on Head Fi; username - cutesillykitten; avatar - Hello Kitty with headphones on.
Having said that I admit to having Robby Rabbit decals on my Suzuki cafe racer when I was in college. It was an insipid little 185cc two stroke and I thought the decal was suitable. Wish I could find the picture of that bike.
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Doc,
Probably not too many head-fi'ers would even know whar a 2 stroke cafe racer is!! LOL
I grew up with Hodaka Ace 100's, Suzuki X6 Hustlers, Honda Super Hawks and lots of smoking 2 strokes!!
From the high banks od Daytona, Roeblng Road Savannah, VIR, Mid0 Ohio etc...those were differnent "fast" times.
and I am still alive to tell about it! Ha!
Alex
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I'm putting together a 1962 Superhawk right now, to run at Bonneville this summer.
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Sweet ride Doc
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OMG! That is sweet!!! I used to ride with a friend that had a superhawk and I had a lowly CB160!!
We went to the drag races and back in the 60's they didnt know what to make of us bike nuts!!
So they just lumped us into one bracket and my friend always beat me handly!!
160cc vs 305 for the super hawk!
I was a young 16yr old that was having the time of his life!!
Ha!
Please post some pix if you get to Bonnie land!!
and BE careful!!
Alex
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I planned to run last year but there was no way I was going to finish the bike in time. So this year I have started much earlier with a lot more commitment. I hope to carry on in your footsteps and get the bike dialed in at the local drag strip this spring. The Hayabusa guys will be shaking their heads, I'm sure. I may have some friends coming to shoot video of the Bonneville run.
My Suzuki was a TS185 dual purpose thumper that I put Avon street tires on, a racy front fender, cut the seat down and reupholstered, put on Tomaselli clipons and a Supertrapp muffler. I ran with a bud who had a CB160. We would ride the back roads between Concord and Berkeley CA, Rick hot shoeing through the turns on that CB like a flat tracker. At the time it seemed like we were so fast. I topped out at all of 80mph in a full tuck, downhill with a tailwind. Then one day a guy on an R90S blew by me on a hairpin. He came up so fast behind me I almost wet them.
I have toyed with the idea of building a CB160 track bike. There's a pretty neat group of old farts who run them in the local road racing club.
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Talk about wetting ones self!!i
The first time I went to Road Atlanta for a 'race' school I was out there on a 600cc bike, and we were mixed in with the then "AMA" 250 gp pros..they were doing a practice test/tune session and I can remember turn 10 at Road Atlanta, downhill with 5 distinct braking markers....I thought I was fast then a 250 gp guy comes blowing by me while i was on the brakes at the 5mark and he goes in down to the 3mark full throttle, then brakes like a wield zombie, turns in and out of the turn he goes, and he looks back at me in the braking area and waves at me!!! OMG....
I got to ride with alot of great racers, held my own by no way was I world famous or in that class....Nicky, Tommy and Roger Hayden, Miguel DuHammel, Dave Aldana, Keith Code and so many more....
So many greatmemories,,,,,bikes, girls, beer, and of course Dynaco!!! Ha!
Alex
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I love this stuff as I sit and watch the snow falll and it reminds me I need to order tires.
BTW Doc, a couldn't help but notice your tank badge...John
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I posted this in another thread but here as well in case it gets buried!!
My beloved CB160 drag bike! Just a bit more than 9 CU IN!!
Solid aluminum billet angle stock for rear "shock"!
Bug Sprayer gas can and the straight pipes were from my Mom's Electrolux Vacuum Cleaner!!!
I couldnt afford anything back then!!
Matter of fact I could have bought (2) of these back then for the price of my Mainline today!!! LOL!
Alex
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Hi,
Does anyone have experience of the Saratov Silver Shield 6C45Pi in the Mainline?
Paul.
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Hi, I found this adapter, 5842->6c45: https://www.ebay.ie/itm/304698401779
It opens up access to Raytheon, Amperex, Sylvania, Mullard, and even affordable WE on Mainline.
Is it safe to use? It is not the only such adaptor
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Is it safe to use? Probably, and sound will come out if you use the adapter. I'm not generally a fan of using adapters like that with high Gm tubes, but YMMV.
I think what you have to consider is that we have experience with the 5842 and it would have cost less to put the 5842 into the Mainline, but we didn't do that.
The 6C45 has not quite twice the transconductance and a bit more gain than a 5842. This makes the 5842 not particularly well suited for the output transformer in the Mainline, and the lower gain isn't particularly helpful either.
For 5842 use, you can check out the Soul Sister preamp design in Valve Volume 4 1998 for reference.