Balanced Lampi Dac - Joe you are famous now

Ian,

I have JRiver and Audirvana+ for native playback. A+ 2.1 is stellar sounding but JRiver 20 is the interface champ (just more elegant than the rest). I have HQP for up sampling/converting. I also have Jplay for when I go PC. I am Mac for the moment. I wishh there was a way to integrate HQ P modulation engine into JRiver.

I also have the spare fuse, BUT I use SR audiophile fuse and some $10 Hong Kong fuses that Gopher turned me on to last year.

You may have a tube imbalance or an interconnect issues as you say. Switch them around and eliminate that possibility…either the tubes or the interconnects.

Do you have 6A3 tubes (like I saw in that FB picture)? If so they are a value champ tube …$50-100 each and 95% of even the very best tubes pairs out there. A real all rounder. See an evaluation a couple pages back by a poster.
At one point we were all crazy for the Sylvanic greenleves and the TunSol black band 6A3s. You can also use the electrically equivalent 6b4g tube with a base adapter. The 6b4gs sound near identical and are even cheaper.
 
Ian,

Glad we got you operational in fast order. As soon as you confirm its not an interconnect I'll get some replacement tubes expedited to you.

In the meantime keep.listening and burning her in, especially the dsd module.

Enjoy!

Fred
 
madfloyd said:
The DAC is working now. The fuse was blown but it comes with a spare.

The only issue I have now is that one channel is MUCH louder than the other. I'm guessing the tubes aren't matched (either that or one of my interconnects is playing rude games with me!)

.
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Any thoughts as to why you lost the fuse...?
 
Thanks for all the info, Norman. I read in the manual that any sort of hifi fuses were a big no-no, but I guess they have to put that there to be safe.

The tubes I have are RCA 6A3's and the single's brand is unknown. Only marking I can see is 5U3C.

The labels on the voltage switch is:
TOP: 2a3/300B (with '643' handwritten)
BOTTOM: 45/101

Can you confirm from this that I should have the switch in the 45/101 position?

Thanks again.
 
Gopher said:
Ian,

Glad we got you operational in fast order. As soon as you confirm its not an interconnect I'll get some replacement tubes expedited to you.

In the meantime keep.listening and burning her in, especially the dsd module.

Enjoy!

Fred
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Thanks, Fred. I have a friend coming over to hear my turntable today (how ironic!) and he wanted to hear it with my Pass gear so I've had to disconnect the DAC for now (I'm evaluating Audionet electronics and I don't have a long enough interconnect to reach from the DAC to my Pass preamp so I was listening to the DAC via the Audionet preamp which is lower to the ground. The Big 7 is sitting on platform on the floor since it won't fit in my rack).

I'm hoping that if I just have the DAC powered on it will burn it in (or do I need to feed it music?).
 
wisnon said:
Actually wattage bands for the self-balancing circuit.

We SE Dac types have been all over this ages ago at AudioCircle.

As I said in my big message 2 days ago, the SE units have a high and low setting, labelled 45 and 2A3 setting respectively, corresponding to something like 4 watts and 6 watts tube circuitry. Watts = VxAmps.

For 45 triode and 101d, use the low setting. For 2A3, VT52 and 300b use the high setting. For 6A3, Lukasz recommends the high setting, but most people were either agnostic or preffered the low setting, even if it means the 6.3v tube is under heated. Theoretically, underheating shortens tube live, BUT as this is not being run at power amp levels, the fact that the tube is plentiful and cheap and that people have several tubes to roll to change presentation…nobody cared about a theoretical shortened life that would mean a change very 4 years instead of every 8 years (if run constantly).

WRT tube rolling, most wont constantly change tubes on a consistent basis, HOWEVER, most will play around initially to find their favourite combinations and stick to that. For example, Mike and Any seem to have settled on the Eklrog 300b as their star DHT in the GG and now I suspect they seek to find out which recti best complements that.
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Norman, I see that you answered my question in this post. I was confused because I understood I was getting 101d tubes.
 
madfloyd said:
Thanks for all the info, Norman. I read in the manual that any sort of hifi fuses were a big no-no, but I guess they have to put that there to be safe.

The tubes I have are RCA 6A3's and the single's brand is unknown. Only marking I can see is 5U3C.

The labels on the voltage switch is:
TOP: 2a3/300B (with '643' handwritten)
BOTTOM: 45/101

Can you confirm from this that I should have the switch in the 45/101 position?

Thanks again.
Click to expand...

With 6A3 tubes, Lukasz recommends the TOP setting (2A3/300b), HOWEVER, most people prefer the bottom setting (even though tubes are under heated). Its a SQ question as both settings work. We the B7 owners have months of experience behind us now to rely on.

Glad that fuses did their job! I suspect Lukasz is just being safe there.

I am not sure the tubes are the problem, as they would have been tested and reflected in your supplied test sheet. If the tubes were unmatched/imbalance swapping interconnects would not change the outputs of either speaker and if the left was lower before, it would still be louder after the interconnect switch. If the right becomes louder after swapping interconnects, I am afraid the interconnects would be at fault. The loud channel would always follow the louder tube. If you swap unmatched tubes around in the Dac itself, the the louder channel would flip.

Do you have other interconnects to try, even cheapo ones? Oh, and get a REGEN!! LoL
 
Ian - congrats on the Lampi. Second, generally speaking, the 6A3 tubes are going to sound "warmer" than the 101D's.

Once you have things sorted out, I would suggest EITHER Elrog 300b's or Takasuki 300b's with the military grade RCA or GE 5U4GT. If you call Brent Jessee, just tell him you want the same rectifier tube that Mike and Bruce bought (military grade RCA 5U4GT).

As for Takasuki or Elrog 300b's, I think we need others to weigh in here on the sound qualities of each. I have Elrog's, but sell the Takasuki's. I've been meaning to buy a pair of Takasuki's for myself, but they aren't cheap ($2000/pair).

BruceLet has both Takasuki's and Elrog's, so I'm hoping he will chime in. I also think there was a thread over on Audiogon where they compared them.

So, as far as "warm sounding" goes, the 300b/military grade RCA or GE Rectifier (the single tube) will be your best bet.
 
Mike, compare that 5u4gt mil spec vs the 5R4GY JAN spec yet?
 
Norman, this is my favorite:

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4b495bb0933ff5b3daf98706bc12a4df.jpg


It surprised the heck out of me it was so good. Warm, with amazing midrange. Better than my 5R4GY JAN spec - which is also terrific. As much as the output tubes make a difference (and they do), it's just as much with the rectifier.
 
I didn't love the VT-244. I have 4 of them I got from my tube guy. It is 4-5 on my list.
 
wisnon said:
Is the Dac working now?

JRiver is a shitty upconversion modulator. Free Foobar is better. Download trial version of HQ Player which trounces them all. It will play via Mac for 30 mins at a time in demo mode and will play for a month in PC as a demo. Signalyst.com
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I can't wait to try HQ Player because i think JRiver playing dsd or PCM encoded as dsd sounds awesome. I could not hear a difference between regular dsd and 2x.
 
Western Electric and Sylvania 274b, U52 from Mullard, Osram 5U4, Mullard 5AR4 (though I have a love hate with this tube), stock 274b, Sylvania VT-244, and then RCA JAN 5U4G (have never seen the RCA JAN labeled VT-244). Best value is the Sylvania 274b. I paid $100 for mine. I am also getting a 5r4g soon.
 
Metal base GZ34 and fat bottle GZ37 are also up there. The latter is a U52 equivalent.
 
madfloyd said:
The only issue I have now is that one channel is MUCH louder than the other. I'm guessing the tubes aren't matched (either that or one of my interconnects is playing rude games with me!)
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We were able to figure out the problem. 2a3 tubes were being run on the 101D setting. Switch flipped and all is good!
 
Wow, if that is so then the SQ must be much better in the correct setting.
 
So much for being able to use 2A3's with either setting.

I was really starting to like the DAC; it brought me the body I was missing. Unfortunately as of this morning all the treble is gone. D-A-R-K. And I have a pretty lean sounding system normally.

It's like all drummers no longer have hi-hats. :-)

Fred tells me the tubes will brighten up as they break in. That's never been my experience but I'll give him the benefit of the doubt. In the meantime I'm suffering and sad.
 
The 2A3 is a nice tube, but I really prefer the 300b's. Ian, to get the treble back, try some 101D's if you can. IMO, 300b's are the best.
 
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