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Post by PinkFloyd on Mar 13, 2007 22:23:03 GMT
Funny but I have taken delivery of a consignment of plain old Chinese 6NS7-GT valves and they sound PERFECT.... no buzzing, no humming just inky black silence so I can only assume, as others have also reported, that the Electro Harmonix 6SN7 just don't want to play ball in the 336i..... off to ebay to put some EH 6SN7 up for sale, I'm sure they'll be perfectly good in another amp ;D
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Post by PinkFloyd on Mar 17, 2007 20:39:41 GMT
48 hours with the Chinese 6SN7 in the front and GE6080 in the back and heck this is absolutely heavenly sound, so addictively listenable, I can see where you're coming from now Fergus. Taken me a few weeks to get there and it would have helped if I hadn't been sidetracked by those humming Electro Harmonic valves but now I'm there it's a good place to be!
It's very much a luxury kind of listen almost so good you feel you don't deserve it, especially not at £130!, the depth is just incredible and that lovely thrummy sound is just..... well..... addictive so flowing, so mellifluous yet certainly not syrupy and vague... in fact the midrange is extremely energetic with lots of little surprises tickling your ears from all directions..... loving it!
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Fergus
100+
Done a David Ike and is now known as Godkin
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Post by Fergus on Mar 17, 2007 21:27:08 GMT
Great to see you've got to the Darkvoice "sweet-spot." Weird, the supposedly better quality EHs turning out to be real duffers. But it's good to get the right ones - eventually. I've had my own humming issues with the 332. I fitted a pair of Sylvania 6AK5Ws the other day, and right from the off a persistent and audible hum. Now, however, it has almost gone - although they're not as good as the best in this family of valves - the MULLARDS or RCAs. Like you, I love the sound of Darkvoice amps. I never get tired of listening to it. I almost have to force myself to turn it off every night. I'm being soppy I know but there's something "living" about a valve amp.
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Post by PinkFloyd on Mar 17, 2007 22:44:29 GMT
Weird, the supposedly better quality EHs turning out to be real duffers. But it's good to get the right ones - eventually. There's a misconception that the Electro Harmonix are "better quality" these things are actually current production being built by people who really don't have the same working knowledge / daily hands on as the people did when valves were the only thing in production. Maybe this is one reason the 336i spits them out I don't know but, for sure, it absolutely detests EH valves and this is well documented if you scour the minutiae in the various 336i threads. I came across adhoc's 6SN7 thread earlier on and it's very good reading indeed www.head-fi.org/forums/showthread.php?t=119638 I'll definitely be trying some of the "GT" versions of the 6SN7.
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Post by PinkFloyd on Apr 8, 2007 22:50:02 GMT
Recently tried some "Tronal" 6SN7 GT and WOW they sound great! Not sure if it's the brand that sounds good or the "GT" extension on the 6SN7. All of the 6SN7 I have tried exhibit a slight degree of hum but, funnily enough, those with a "GT" extension are as quiet as a mouse. I'm still a bit concerned with the heat build up (mainly in the transformer) after a good few hours use. These guys are intended for 220V voltage whereas UK voltage is more along the lines of 240V (maybe more maybe less dependent on your supply) I tried the 336i with a voltage of 217V and she run relatively cool / warm over a five hour period. Fed with around 240V she run pretty hot over the same 5 hour period....... Not good news for component longevity and I think darkvoice should maybe make a 240V version of this amp solely for use in the UK. I'm running 100V / 100uF Nichicon non polar output caps bypassed with 4.7uF 250V EVOX polyprops and the sound is a LOT better compared to the stock 3 x 10uF film caps per channel..... 330uF per channel would be better but considering I'm only listening to high impedance Senn HD-600 out of this amp 100uF is more than enough. If I were a Grado fanboy I'd definitely be implementing 330uF or more in this position. Sound quality is fantastic but the heat still concerns me..... I may have a workaround for UK users which I will publish shortly
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Post by PinkFloyd on Apr 14, 2007 11:30:10 GMT
Just got some NOS "Tronal" 6SN7-GT best sounding valves so far with the deepest bass and lovely flowing midrange.... cheapish too
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Post by rossman on Apr 14, 2007 18:14:27 GMT
Hello, I have joined the forum as I have had a THA 336 (not I version) for a while now and only recently started to try different 6sn7 valves. I did buy an RCA for the rear almost immediately after buying the amp but the Sovtek 6sn7 that I tried hummed badly so I just returned to the stock Chinese valve. Anyway after some experimentation I have found a Ken Rad VT231 that is absolutely silent. Before that I had tried a Tung-Sol and Raytheon GTBs that hummed but were getting better over time. I ordered a EH before I read about the problems with them, fortunately I was able to return that for a refund. However once I had the Ken Rad in place I have been happy with the sound. I might try a Tronal if I can get one cheaply enough. I am using HD-600 with stock cable for now. Source is Pioneer PDS-703 through Meridian 203, the 203 only came this week so I am looking for a good digital cable to go with it. Any recommendations?
Paul
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Post by PinkFloyd on Apr 14, 2007 20:14:09 GMT
I did buy an RCA for the rear almost immediately after buying the amp but the Sovtek 6sn7 that I tried hummed badly so I just returned to the stock Chinese valve. Some of them do have a tendency to hum Paul, more so the 6SN7 and not so much so the 6SN7-GT, have you fitted cathode resistor bypass caps? These greatly reduce hum and make valve rolling a lot less hit and miss.... very easy to do too all you do is solder in two caps..... 35V 100uF are fine for the job I can send you a couple no probs.
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Post by rossman on Apr 15, 2007 19:21:50 GMT
My technical knowledge is very limited and my soldering skills are pretty poor as well. If I was going to attempt this I would need plenty of guidance. I have made a few cables up and my soldering is getting better but I would be nervous about doing components. However it is something I should work to improve. I have some circuit boards that I was going to use for practice but never seem to find the time to do. I use a silver solder but feel that it takes too long to melt and everything seems to get too hot.
Well I'd be interested in trying a tronal valve after your comments above.
The Darkvoice does run warn after a few hours. I'd always been a bit worried about the voltage difference but as it worked ok I left it at that.
Paul
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Deleted
Deleted Member
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Post by Deleted on Apr 15, 2007 20:40:56 GMT
Mike It's been a long while since I worked with valves, but doesn't fitting a cathode bypass capacitor increase that stage's gain ? Perhaps that's not a bad thing in the gear you are discussing. O.K, I will go away and butt out of a discussion I shouldn't have butted into ! BTW, have you rediscovered the night sky ? SandyK
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Post by PinkFloyd on Apr 15, 2007 22:52:57 GMT
Mike It's been a long while since I worked with valves, but doesn't fitting a cathode bypass capacitor increase that stage's gain ? Perhaps that's not a bad thing in the gear you are discussing. O.K, I will go away and butt out of a discussion I shouldn't have butted into ! BTW, have you rediscovered the night sky ? SandyK A good all round compromise in this position is 100uF / 35V.... to my ears there is no change except you can employ a wider selection of valves without suffering any hum..... Plenty of shit on a "cathode bypass capacitor gain" Google search I won't add to it.... in this particular app 100uF is right on the money to my ears (I concur with "Fitz") it cures the "hum" and sounds great I have no reason to question it or analyse it.... too busy gardening at the moment.
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