Breathing new life into my Counterpoint amp
Ater re-tubing my Pre Amp, I still though there was something missing. I knew the amp should sound better but was not real sure where to start when looking at the tubes. It uses 2 EZ81 Rectifiers and 2 6DJ8 tubes.
I was emailed by a member of another board out of a discussion on modding Counterpoint gear and given some suggestions. This guy suggested that I try a direct replacement tube, 6CG7/6FQ7 RCA Cleartops. He described nice fat bass and good soundstage. At first I had trouble locating them and after more discussion, he offered to send me a little care package of used tubes to try.
In about a week, I got a little box with 2 NOS Tungsram EZ81 Rectifiers and several varieties of the 6CG7/6FQ7 tubes including 2 of the RCAs that measured in the Good range. I replaced the Rectifiers which were the original 90s era with Counterpoint labels on them and also dropped in the Cleartops.
I happen to be running with my Dynaudoio 82s which I would normally switch to the Stratos amp because it never really sounded like the CP-Danes were a good match.
Well right off the start I was blown away. The Danes opened up. What I always thought were their signature rolled off highs was almost gone, the midrange opened up, and I now had deep fat bass that sounded like each bass note should sound.
After a week, I decided to seek out a set of these tubes and found some NOS early 60s in matched sets from audiotubes.com for $48 plus shipping. They will measure as NEW when they were manufactured and matched within 5%. I should have them by early next week if not sooner.
The 6DJ8 tubes I am replacing were put in when I purchased the amp and had it brought back to life by RHB Sound Dezign and they were new production Electro Harmonix $10 tubes that I now know are lifeless for this amp.
I will post another update when I get the NOS babies in place. I am also real excited that when I put my Clearfields back in the mix, they will also have bass they never had along with a more awesome midrange.
Tubes are fun for sure, I can't believe I am buying brand new tubes that are 50 years old, like myself.
Well it's obvious nobody cares, but here is the update anyway.
My 50 y/o NOS tubes arrived on Saturday. The pins were a tiny bit oxidized and instead of using de-oxit, I tried a little trick my brother used for cleaning contacts. He would use a rubber eraser. So I took a pencil and drilled a tiny hole into the center of the eraser smaller than the pins on the tubes. I pushed each pin into the hole and rotated the pencil to remove the oxidation and it looked to work great.
I dropped the tubes in on Sunday and as per the papers that came with the tubes, they are a wee bit edgy. That will go away within about 100 hours time.
The sound? Yes, everything I gained from the used tubes I was sent as a care package was there but more of it all as I expected with tubes measuring 20% or more stronger.
My Dynaudio 82s have one heck of a sound now unlike ever before. Plenty of bass, fat bass with nice resonance. Much more midrange than ever and less rolled of highs.
Although the 6CG7/6FQ7 tubes are a tiny bit different in electrical properties, they are recommended as direct replacement of a 6DJ8 tube by Counterpoint. If you are into rolling and have a Pre Amp or Power Amp that uses a 6DJ8, you may want to try some of these NOS tubes before they are all gone.
I got a matched set from a reputable dealer, Brent Jessee Recording, BRENT JESSEE RECORDING HOMEPAGE. I may have paid a bit more than on eBay, but I trusted this seller way more and have always heard good things about his NOS tubes.
Glad to hear that the tubes worked out for you. Tube rolling can be fun and very rewarding when the sound is improved. I have bought some NOS RCA Black Plates from Brent Jesse and one was clearly bad and obviously not tested. The bottom line is that it is a crap shoot when buying NOS tubes even from reputable dealers.
HyFi, I have many different NOS 6CG7 tubes and have loaned some out to Mr.P. If you ever become interested in further rolling, let me know and I can loan you some tubes.
Pass Labs X250 amp, BAT Vk-51se Preamp, Pass X-1 Preamp
Magnepan QR1.6 speakers
Van Alstine Ultra Hybrid Tube Preamp and Ultra Hybrid Tube DAC
Martin Logan Original Dynamo Sub
Parasound A21 amp
Vintage Luxman T-110 tuner
Magnepan MMG's, Grant Fidelity DAC-11, Class D CDA254 amp
Monitor Audio S1 speakers, PSB B6 speakers
Vintage Technic's Integrated amp
Music Hall 25.2 CDP
Adcom GFR 700 AVR
Cables- Cardas, Silnote, BJC
Velodyne CHT 8 sub
Hopefully you got your money back on that bad tube.
Originally Posted by blackraven
Thanks for the offer, I may take you up some day when the waf sticker shock wears off a bit. They are sounding better every hour and I am starting to re-like my Dynaudios a bit.
Great news! Tube rolling is a hobby within a hobby. I've never owned a tube amp that I didn't upgrade the tubes ASAP. New tube gear is often sold with cheap tubes as the manufacturer knows they are going to be replaced anyway. It's much the same with used tube gear as the seller often will not include his most prized tubes.
I encourage anyone who rolls tubes to invest in a tube pin straightner. It's easy to get a bent pin and using bent pins can cause a loose socket connection. The tiny dental brushes that clean between your teeth make excellent socket cleaners when dipped in Deoxit or contact cleaner.
On the subject of Deoxit, I recently learned that a spray can of the stuff will lose it's propellant within a year or two. If that happens do not throw the can away if there's still some remaining. Instead make sure all the pressure is released and then drive a big nail in the nozzle valve and drain the contents into a plastic squeeze bottle. It works as good as ever.
I don't want to go nuts about it but I knew there was something just not quite right. The amp was designed long before new production crappy tubes were. The EH 6DJ8 may be an ok tube for some applications but sucked at the job in the Counterpoint.
The new 6CG7/6FQ7 tubes just keep sounding better and stronger as they break in. I'm really happy and will be rolling in the Clearfields soon for the real surprise.
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