Message started by Rivieraranch on 08/04/13 at 19:15:55

Title: DYING 6BQ7A
Post by Rivieraranch on 08/04/13 at 19:15:55

I have been using a GE 6BQ7A as an input tube for my Superzen. Unfortunately he other day I heard a faint scratching sound from the speakers when nothing was playing. I did not know right away whether it was a power tube or the input. I cleaned all the tube sockets and reinstalled the tubes. I heard the same sound. So I replaced the input with a 1976 6N1P-EV and the sound went away. Strange how a GE tested by Tektronics could go bad so soon.    

Title: Re: DYING 6BQ7A
Post by jameskk on 09/11/13 at 18:34:33

do you think you were getting better sound with the 6BQ7? I had a bad 6n1p when I first got my superzen , about 5 hours out of the box. replaced it with another 6n1p and have not had a peep out of it since. just the best music EVER!!!!!!!!

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 09/12/13 at 00:21:16

I think the tube was not bad after all. I heard the same fuzzy sound coming out of my Superzen. I removed the ZStage to isolate that. The sound persisted. Then I switched the bias switch on and off a few times and the sound went away.

I have been using the 6N1P-EV in the input position. The 6BQ7 sounds a little less warm. That is the main difference.

Title: Re: DYING 6BQ7A
Post by jameskk on 09/21/13 at 11:51:56

Ill have to try that then . I think I have one or two of them here but not GE. I'll be damned I do have a 6BQ7, not an A and it is a GE. always thought GE's were very neutral sounding. I love the way the superzen is sounding right now .Just noticed that I have 2 RCA 6BQ7's also. sorry I guess you were looking for an answer to that from Steve. Installed the 6BQ7 anyway just to listen.

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 09/21/13 at 13:34:39

You will find it just a little more dry and detailed than the 6N1P

Title: Re: DYING 6BQ7A
Post by jameskk on 09/22/13 at 13:21:28

this tube seems to glow brightly in this amp, have you asked if its safe to use ?

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 09/22/13 at 13:41:43

Yes it is. The reason I stumbled on it in the first place is that I was looking for a US tube that was electrically similar to the 6N1P for testing purposes. This one came up. I've used them in my office amps and home amps without incident. Glowing brightly is fine. If the plates were red that is another story.

Title: Re: DYING 6BQ7A
Post by jameskk on 09/23/13 at 13:06:45

yes , and thanks , the small time I listened was probably the closest to the 6n1p I've heard. Or like you said a drier sound which is also good for me. nice to have an alternative to the 6n1p.Finally!!!!

Title: Re: DYING 6BQ7A
Post by jameskk on 10/15/13 at 10:38:40

Hey RR if it's any consolation I got a supposed 6bq7 That was NOS NIB RCA. Reaked havoc  in my superzen for about a minute . Took it out and smashed it .  yes bad right from the get go!!!!

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 10/15/13 at 12:15:01

I can send you a known good one.

Title: Re: DYING 6BQ7A
Post by Lonely Raven on 10/15/13 at 14:21:12

Seems like a good price.

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 10/16/13 at 11:30:31

These are a much better bet because they were screened for oscilloscope use.

Title: Re: DYING 6BQ7A
Post by jameskk on 10/20/13 at 12:56:58

I went viral on these 6bq7's and got some great ones brand new Brimars from a guy in Florida, you might know who im talking about. One  friend never got a bad tube from him. one question I have though is will we see Steve changing these amps rectifiers over to solid state one day since the tori mono's have that . I know its a more inexpensive endeavor , not nessessarily better sounding???? not a U.S. tube , so I got a half dozen RCA black plates also great!!!!!! THANKS!!!!

Title: Re: DYING 6BQ7A
Post by Lonely Raven on 10/20/13 at 14:32:02

I picked up that 10 pack that RR posted above - just got them last night.

One tube is blue arcing, the rest work fine - one sounded exceptional. Like, *wow* exceptional. I set it aside to try and figure out what's different about it. It's probably nothing more than a volume thing, but still, worth a look.

Title: Re: DYING 6BQ7A
Post by Rivieraranch on 10/21/13 at 03:20:58

I bought ten of these as well some time ago. Maybe the blue arcing tube needs to burn in. One of mine tested bad; low emissions. The rest were fine.

Title: Re: DYING 6BQ7A
Post by Lonely Raven on 10/21/13 at 12:26:40

I'm not going to chance it. I messaged the seller and he said to toss it out, he's sending a new one. I just left him positive feedback.

Even with only 9 good ones, this is still quite a deal. I do like the dry, detailed sound these have and I plan on sharing them with my good friend who also has an SE84-A and probably hasn't changed his tubes since I gave him a set 10 years ago.

I'm sorta on the lookout for another SE84-A, I've been wanting to run a pair of these in mono since day one to see what closer to 6 watts would sound like. But saving up for my Mystery amp comes first.

Thanks again for pointing these tubes out!

Title: Re: DYING 6BQ7A
Post by jameskk on 10/27/13 at 12:34:20

I'll have to try this tube in the rest of the zens I have , not totally discounting the 6n1p,because IT is a very stable tube in the Decware  zens and torii amps. We must commend Rivieraranch for finding this fine alternative . Now to keep them from DYING?!?!?!

Title: Re: DYING 6BQ7A
Post by Lonely Raven on 10/27/13 at 21:13:32

So I had a listening session using these tubes with a good friend of mine that also has an SE84-A (unmodified), plus a non-audiophile friend with decent ear. We decided these tubes aren't warm enough or liquid enough (compared to stock 6N1P), but they are great for detail. Definitely nice to have around for a different flavor. They also run cooler with less heater draw.

Title: Re: DYING 6BQ7A
Post by Lon on 10/27/13 at 21:30:52

That has pretty much been my take with this tube type as well. And I put about a hundred hours or more on a pair. Not my cup of tea. But works well (electrically) and may be just the thing for someone else.

Title: Re: DYING 6BQ7A
Post by jameskk on 12/16/13 at 12:20:33

Maybe it doesn't work in push ,pull amp (torii) , but it certainly does in the Superzen ,and maybe all Zens

Title: Re: DYING 6BQ7A
Post by Lon on 12/16/13 at 13:20:41

They work nicely in a pair in the CSP2 I have, though not as well in the input position.

Title: Re: DYING 6BQ7A
Post by jameskk on 01/25/14 at 12:32:23

I know its late for this , however I always fall back to the 6n1p , just to make sure , the 6nip is back in there.

Title: Re: DYING 6BQ7A
Post by Lon on 07/13/16 at 15:13:44

There are some nice deals on these tubes on ebay lately. I revisited this type with a sleeve of RCAs (branded Motorola) and they work really well as driver tubes in the CSP2+. Work well in the input tube position as well if you are needing more detail and drive. As noted above a bit deficient in the lower frequencies in this position.

Ultimately I prefer to use a pair of CCa in the driver position and a Siemens 7308 as an input, but even though I got all three of these at great low prices they cost 15 to 20 times as much each.

Title: Re: DYING 6BQ7A
Post by will on 07/14/16 at 02:05:00

The late 50s RCA 6BQ7As are probably the warmest I have, pretty warm actually. Also some earlier GEs I have are warm, but more open, and some Westinghouse are relatively darkish mids down and open mids up. Seems most of them tend to have a bump of upper mid energy. British Brimar, Ediswan and Utron tend to be more open, with good frequency balance within the type...  I liked this tube a lot for quite a while, often in the CSP3 input, but in the outputs too. They were really great when my system was tending a bit dark with the other tubes and cables and all I had in.

Interestingly, I put an Ediswan 6BQ7A in the CSP3 the other day to open things up due to burnin muck. Sounds great with this setup.

I think they are really good tubes in general and amazing value for the quality if you need to open and speed up the sound some. If the balance of the rest is a bit darkish/denser/slower, they can balance things really nicely. If the balance is more neutral with 6N1Ps, they may be too bright/open, some of the British ones tending to be a little more so, especially the Brimars I have. I think compared to most inputs, these tend to create more spacious mids and top a little more than most.

I never liked 6N1Ps because of clipping in my Torii at too low a volume for me, but also because they are missing micro detail I need, whereas 6BQ7As tend to be good at micro detail. The thing I don't like is a little veil in the mids of some of the is a weird sort of veil, the notes quite articulate and with a lot of micro information, but with a darkish feel to the low mids.

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