Hitachi 6SN7GTB question: I just won on auction 3 NIB Hitachi 6SN7GTB black plates ( re-branded as Tel-Rad ). These are the bottom square getter ones vs the more common top getter ITT branded Hitachi version. Lots of posts here on the Hitachi's, but often it's not clear as to which of these...

joseph69:   I would take-up Skylab up on his generous offer on send you a pair of fat bottle 6DF7's.  I had a pair of RCA's from the late 60's in my Woo Audio WA6 and they are very good. They have good bass and a nice full lively sound with good dynamics, and a nice warmth without getting too...

joseph69:   I have a Woo Audio WA6 and have been using a Mullard GZ32, ( same as a 5V4G in the Mullard as I understand it ), and love that rectifier. I too am using 6SN7's in the WA6 and my favorites are a set of Brimar's from the 50's and Ken-Rad's ( clear glass ) VT231's. Have tried 4 other...

KMSV: Ditto Dubstep Girls recommendation of the GZ32/CV593 ( in a Mullard ).  I have a Woo Audio WA6 and had a Amperex/Mullard 1958 GZ34 and I prefer the GZ32 due to it's wonderful warm mid-range.

I posted here a few months back after reading Dubstep Girls excellent rectifier comparisons. I have a Woo Audio WA6 with the 6SN7 adapters and prefer the 6SN7 sound.  Since that post, I purchased a NOS Mullard GZ32 ( 1955 vintage w/ square getter ) in it's military version, CV593. I have read...

Thanks Dubstep Girl for a well written rectifier comparison.  Should become a great reference thread here. Great job!   I would also like to add a often over-looked rectifier, a Brimar ( STC ) 5V4G/CV729/GZ32.  I have the CV version from 1955 and it is a pretty decent rectifier in the right...

Yes, it's a black plastic base GZ34. I've looked all over the web and the F30 1957 code is next to impossible to locate. Boy, don't I wish it was a metal base GZ32, now that would be something    Thanks for your input on the Brimar 5R4GY. I understand it also has a expansive soundstage and a...

Dubstep Girl:   My apologies! I mistakenly entered GZ32 for the Amperex Bugle Boy instead of the correct GZ34. Sorry about that. This comes from being an older timer in my sixties I guess. None the less, the F30 part is the clincher here as most start with F31. The date code is located at the...

I will take a photo and post, but it has a black plastic base and the smooth plate structure of the Mullard and Amperex of the late fifties. My research shows it to be a fairly rare tube - the date code is F30 X7H, so it's a Philips Sittard Holland plant, 1957 ( August ) made rectifier. It would...

This is my first post on this old thread as I just purchased a used WA6 from another Head-Fier here a few months ago. It's a older WA6 from 2007 and has the smaller driver tube holes, so I am using a pair of Tubemongers socket savers to allow me the use of a pair of RCA fat bottle top getter...

I am considering buying a new La Figaro 339 ( new upgraded model ) and was wondering if anyone who has owned this amp has had troubles with it ?  A few posts here mentioned issues new out of the box, but things have been quite as late on this amp. Besides problems, would love to hear how you...

I have both a Cayin HA-1A and a ASL MG Head DT/OTL MKlll.  Both have vintage tubes installed.  I prefer the MG Head ( in the OTL mode) over the much more expensive Cayin for use with my HD600's. It warms up and moves the midrange a bit more forward, and just sounds more involving. Of course...

I really like the RCA 6BQ5's in the Cayin. These would be the older mid-sixties, gray or black plate round cylinder type. The RCA's have a sweet top end, clear-mids, and punchy bass. As compared to Mullards, which I also have and enjoy, the RCA's are a bit more dynamic, but not as warm sounding...

The speakers I'm guessing were more than likely a low-impedance (4 ohms), low efficiency set. Small, sealed enclosure sets are by nature in-efficient. The Cayin with its small output needs at least an 8 ohms (16 ohms preferable, and of a very high efficiency rating). A vented, horn type loading...

I have a recently purchased Cayin HA-1A, which I have already started tube swapping. Based on the circuit topology, I assume that of the two pre-circuit tubes, the 12AX7 position would have the larger sonic impact over the 12AU7? Wrong assumption? For the record, I'm using a RCA Command 5751...

Man, you guys were right! My thanks to all who posted their opinions on this combo. It really takes the 701’s to another level. I’ve only had the Cayin a few days now, but even with the stock tubes it sounds nice. I have Mullard EL84, s, RCA, Tung sol, and Sylvania 5751’s, and just ordered a few...

I received my AKG-701's a week ago. Very nice cans. Agree with many of the observations here at Head-Fi. One issue I find interesting is the long burn-in time suggested my many. During one of my thread searches here, I recall AKG's tech's theory that the sonic changes resulted from the gradual...

I have a mild case of tinnitis in both ears. I played in rock bands up to the time I was about 30 years old, (I'm now 52). I really dont notice it during the day as any ambient noise covers it up. However when in a dead quite place, or at night lying in bed ,it's easy to let myself get "focused"...

Blasyrkh The quality control issues are well documented in posts here at Head-Fi. But the main one was noise (hum) in the early "Heads" that it turned-out was caused by the wiring to the front power switch running beneath and too close to one of the tube sockets. That was overcome by design...

I have a ASL MG Head OTL MK3 that I have owned from new for about a year. I use it with both a Sennheiser 600 and Sony CD3000 headphones. The sound is excellent with both. However the best match is with the 600's. I know that the MG head has fallen out of favor with many here at HeadFi...

I recently tried the headphone jack of my rarely used Proton D940 receiver, (NAD designed and built at the same plant NADS of the mid-eighties were), and was surprised at the quality when used with both my Sennheiser 600 and Sony CD3000 cans. Warm overall sound quality, which sounds particularly...

My research and long love affair with tubes says that the Cryo treatments are in the same league as using a green highlighter on CD's to improve the sound. In otherwords, "voodoo magic", not good science!!!

Go find a good used tube amp. The Senn's love tubes! Really opens them up.

I recently bought a pair of CD3000's, and really dig their wide soundstage. Much closer to speakers than most headphones I've owned, which includes my current Senn 600s, and past owned Senn 580's,Grado RS-2, 325, 80, and AKG K340 & 240.

Oldears stated it well. There is a gradual decrease in dynamics, and the overall sound starts to sound compressed. Preamp tubes will often start to roll off the frequency extremes, and some will get noisy. But as oldears mentioned, it's gradual enough that you may not notice it right away. It...