New tubes for ARC REF2SE

Mike

Mike

Audioshark
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Today I received my Winged C 6550 and 6H30P-DR's and installed them in my ARC REF2SE. I listened for an hour to some familiar LP's and I was pleasantly surprised of the differences - for the better. Midrange is more forward, the sound is meatier and more classic tube sounding and ironically, better balanced through a slight reduction in bass. The most surprising change was how much quieter the new tubes are - and the stock tubes aren't noisy!

I hope to spin some more vinyl tonight - but so far - a very worth while investment!

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I'm playing Keb Mo's self entitled album and everything sounds better - BUT - on the LP, the tube noise is a bit noisier.
 
Mike said:
LMAO! Placebo affect? ;)
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Absolutely! :)

Just kidding of course. Although I see in your next post you said something about some noise... It could be a bad tube. Try swapping out a NOS tube with one that was in there before. Do this for each tube and you may find the culprit. If one is noisier than the rest I would return it for a different tube. I bought some NOS RCA 12AX7's a while back and they lasted about three months before getting all noisy like that. Ticked me off!
 
dlb2 said:
Absolutely! :)

Just kidding of course. Although I see in your next post you said something about some noise... It could be a bad tube. Try swapping out a NOS tube with one that was in there before. Do this for each tube and you may find the culprit. If one is noisier than the rest I would return it for a different tube. I bought some NOS RCA 12AX7's a while back and they lasted about three months before getting all noisy like that. Ticked me off!
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It seems to have quieted down. Might have been something on the record? I changed to another LP and now its back to being super quiet.
 
Mike said:
It seems to have quieted down. Might have been something on the record? I changed to another LP and now its back to being super quiet.
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The 6550 is used as pass element in the series regulator of the REF2 - unless your old 6550 was faulty it should not change the noise of the preamplfier significantly. If the 6550 or the 6h30 were not previously burned-in sometimes they can go through some slightly noisy periods during the first hours, as the cathode settles by use. If a 6550 becomes noisy it is also immediately transmitted to the output. Did you notice noise in just one of both channels?

We should also consider that sometimes a change for a better, more fluid and better defined sound can make an LP sound as if there is less noise.

The 6h30s are supposed to last well over 4000 hours, but the 6550 should be replaced after 2000 hours.
 
cmalak said:
The 6H30-DRs that Mike bought are rated to last 10,000 hours.
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My first set of 6h30 in the REF40 still measured perfect at well over 6000 hours, but when one of them became noisy I replace all of them and it was a great improvement in sound quality, although it was the same type and brand of tubes. Many people report that long before their measured end of life tubes loose sound quality, I have no experience in these matters.
 
I'm sitting here kicking myself for never rolling the tubes in the REF 250's or REF 10. They sounded great, but geez, how much better could they have sounded?

I think a lot of tube gear manufacturers are focused more on tubes that are RELIABLE. Of course sound is important, but I don't think it is the number one deciding factor - reliability is. When they buy a batch of 1000, they need to get as many as possible to meet spec. They also need to be able to buy NEW. They aren't going to be spending their time farming NOS like us. I will admit, I kind of forgot about tube rolling of late as I became a bit convinced that the stock tubes must be the best.

As these new tubes have warmed up, boy oh boy is the sound rich and full, but still retaining wonderful detail. Bass is ever so slightly "less", but more balanced top to bottom, which I quite like. The midrange is dramatically better. Much smoother on top too.
 
Question Mike,,,Does you amp require rebias since you changed the tubes ? They are output tubes and since they are, many amps require it unless they use Resistor (cathode) bias ...?
 
ohbythebay said:
Question Mike,,,Does you amp require rebias since you changed the tubes ? They are output tubes and since they are, many amps require it unless they use Resistor (cathode) bias ...?
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There is no way to bias the tubes on the ARC REF 2SE - that I am aware of. If someone knows otherwise, please let me know.
 
Rob/Mike...the 6550 tube in the Ref 2SE is being used along with another 6H30 in the power supply. The other 6H30s (4) are used in the phono preamp circuit as small signal tubes. So no biasing/re-biasing to be done.
 
cmalak said:
Rob/Mike...the 6550 tube in the Ref 2SE is being used along with another 6H30 in the power supply. The other 6H30s (4) are used in the phono preamp circuit as small signal tubes. So no biasing/re-biasing to be done.
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Thanks Cyril! It sure is sounding amazing!
 
cmalak said:
Rob/Mike...the 6550 tube in the Ref 2SE is being used along with another 6H30 in the power supply. The other 6H30s (4) are used in the phono preamp circuit as small signal tubes. So no biasing/re-biasing to be done.
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That answers that for both of us !!! Cool...

Mike, yes...roll some tubes

Can I say I told you so? LOL

Many people think the manufacturer designs some spec that has to be matched by the tubes they supply. Not so. The tube type all have the same voltage specs, etc...what is different is design and flavor.

Sort of like wine. Every bottle of say Pinot Noir may be 12% alcohol but each has its own flavor, yes? Same with tubes.

If you can (if your other units take them) try some OLDER new old stock tubes...unfortunately, the 6550's are more rare - But there are NOS tung sol , GE...

For other tubes, like 12AX7's, 12AU7's...wow..talk about flavor and spice...LOL
 
dlb2 said:
Glad to hear the new tubes are working out Mike. I wonder what some NOS tubes would have done for the Zesto...
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That too! OMG. I rolled tubes in the 2301's and it made a nice improvement. That was the last time. Clunk to the forehead!
 
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