List Your RSA B52 Tubes

[vcoheda]

got my new tubes - 12AU7A RCA Clear Tops. plan to use them this weekend.

also got some other goodies for my amp. i picked these up upon recommendation of another B52 owner.

Absorb-GEL™ Vacuum Tube Damper is an innovative solution resulted from several years of extensive research and experiments by Allnic Audio Lab, significantly reducing vacuum tube micro-phonic noise.

look at the pretty graphs.

i also purchases these - Rothwell XLR Attenuators to lower the gain and give me more volume control.

Balanced (XLR) attenuators are specially designed for audiophile line level balanced equipment and use gold plated contacts and precision resistors, hand-wired with silver plated oxygen free copper wire, insulated with PTFE.

 

[shaizada]

I see you got a hold of the Allnic Dampers. They are awesome if any tubes are actually microphonic. The most important thing is that they don't HURT the sound in any way....that's the most important thing I was looking for.

Also, I see you found an interesting set of attenuators for the gain of the B-52. I'm using the B-52 with 96db efficient speakers so even small turns of the volume knob can produce a lot of volume. Those Rothwells have mixed reviews, but definitely share your experience with them when you get a chance. Do they compromise the sound in any way?

My experience has been to try and keep the sonic chain as simple as possible. The more "stuff" the signal has to go through, the less purity is maintained.

Here is one article on the Rothwell that made me stop before I purchased a set

Rothwell In-Line Attenuators by George Pappas

 

[vcoheda]

^^ seems to be all positive so far.

 

[BigEat]

Hey Guys,

I find the 5687's very hard to find. You?

 

[vcoheda]

^^ go to this link https://www.tubeworld.com/index_high.htm and then click on KUHL-TUBE STOCK. they appear to have matched tubes in stock of the following.

5687WB Tungsol Branded Raytheon 1950's "U" getter halo

JAN-5687WB GE 1970's

5687 and JTL-5687 Tungsol black plates "U" getter 1950's

 

[vcoheda]

Quote:

Originally Posted by shaizada /img/forum/go_quote.gif I see you got a hold of the Allnic Dampers. They are awesome if any tubes are actually microphonic. The most important thing is that they don't HURT the sound in any way....that's the most important thing I was looking for.

i actually prefer the sound (slightly) w/o the tube dampers. but my tubes aren't microphonic. i just bought the dampers b/c i noticed that they were being sold by the same seller of the rothwell attenuators and figured that at some point i will have some microphonic tubes and it will come in handy - maybe. we'll see. the rothwells are great though. much better volume control.

 

[vcoheda]

just tried my RCA Clear Tops.

one of the tubes exhibits significant static - not happy. why pay a premium to buy from these online places over ebay if you are still going to get faulty stuff. i contacted the vendor. we'll see how quickly/easy this is resolved.

 

[earwicker7]

Quote:

Originally Posted by vcoheda /img/forum/go_quote.gif just tried my RCA Clear Tops. one of the tubes exhibits significant static - not happy. why pay a premium to buy from these online places over ebay if you are still going to get faulty stuff. i contacted the vendor. we'll see how quickly/easy this is resolved.

I think tubes get damaged in shipping if someone sneezes on them the wrong way. If it's a reputable dealer, they'll exchange them... just try to make them cover the shipping costs.

 

[sacd lover]

Quote:

Originally Posted by earwicker7 /img/forum/go_quote.gif I think tubes get damaged in shipping if someone sneezes on them the wrong way. If it's a reputable dealer, they'll exchange them... just try to make them cover the shipping costs.

Tubes are actually quite tough. But, you have to pack them properly.

 

[shaizada]

i Hope it works out for you David.

 

[vcoheda]

i have a pair of replacements for my RCA Clear Tops on the way.

i also picked up another pair of the same tubes for comparison purposes. in addition to those tubes, i just recently purchased these.

12AU7 Amperex Bugle Boy Holland

5814A GE 3 Mica Blackplate


should give me plenty to play with, for now.

 

[vcoheda]

have been using the RCA Clear Tops for the last few days. compared to the Mullards, they are more forward and with seemingly better detail. the music seems overall crisper. but there is also at times a certain edginess or brightness to things and the tubes are somewhat microphonic. the Mullards are warmer and the music is overall smoother sounding, but there also seems to be a certain lack of preciseness or inner detail. they are dead quiet though with no noise whatsoever. as of now, i prefer the Clear Tops. i have a few more tubes coming my way. will be interesting to see how they compare.

 

[vcoheda]

just received some more tubes - the amperex and GE blackplates. and of course one of the amperex tubes is bad. the GEs are fine. i'm having bad luck buying tubes so far and a lot of these tubes have not been cheap. i was looking forward to the amperex tubes as well. the bugle boy hollands are supposed to be very good. well, the GE blackplates so far sound pretty good. similar to the RCAs but better bass and a more forward or prominent mid range. the RCAs seem to have a better top end. Also like the RCAs a bit microphonic. it's amazing how dead quiet the Mullards are. maybe that is not the norm.

 

[vcoheda]

picked up these tubes recently. they are CK-5814A Raytheon 3 Mica Black Plates.

the 5814s seem to really bring out the midrange. very much like these tubes. both these and the 5814 GEs are probably my favorite tubes. still looking for a pair of amperex bugle boys. i had a pair but one tube was bad. i did get a refund from the seller, so no loss.

 

[vcoheda]

Quote:

Originally Posted by sacd lover /img/forum/go_quote.gif If you really want to improve the amp see if the amp can handle the extra heater current demands of the 12BH7A. The 12BH7A is a much better tube than any 12au7 I have used in my SP or modded Doge amps.

i just asked ray about this and he said that the 12BH7/12BH7A was a suitable replacement for the 12AU7s in the input position on the B-52 (tubes 1 & 2). so i think i will have to track some of these down.

any recommendations?