[Dawgfish]

I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s. If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive. I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.

 

[SHIMACM]

I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s. If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive. I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.

I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.

 

[Dawgfish]

I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.

Gotcha. Hopefully some of the others will have some advise for you. I haven't tried anything buy 12AU7s or 5814s in any of my Bottleheads.

 

[steve468]

Hello guys!

I have a problem when I use valve drivers with adapters in my Crack w/speedball.

There is often a kind of hissing/static noise in the headphones, which, to temporarily resolve, I have to unplug and reconnect the headphones to the amplifier for the background to go back to black.

This happens with all my headphones.

This is very annoying because I have to do this procedure at least 5 times during my listening session.

The problem occurs when I use 6sn7, 6f8g, 6j5g/l63 valves with 6f8g to 12ua7, 6j5g/l63 to 12ua7 and 6sn7 to 12ua7 adapters.

When I put 12ua7 type valves I don't have this kind of problem.

Has anyone had this kind of problem and managed to solve it?

It could be the actual adapter. I went through 3 6sn7 adapters before I got one that didn’t have a hum. The good one was from Garage 1217. Though I was fine with my first 6f8g adapter. It is a bit weird that it happens for you with ANY adapter…

 

[raindownthunda]

Wow, yours looks great!! The tube chasing is never-ending. I did this with guitar amps for YEARS and amassed a completely unnecessary amount of tubes, of which 99% just sit in a box, LOL!! I'm trying hard to not do anything similar with the Crack, but I think I'm too late.

I went through a family of power tubes and they're all really great. The 5998 (Tung Sol & Chatham) is likely my favorite for separation, detail, and high-frequency clarity. The 6080 family hits harder in the lower end and really pushes my ZMF Auteur and VO in a good way, with lower end resonance. The 6as7g is in between the other two. A good medium.

For preamp, I've enjoyed the RCA clear top 12au7 for a long time, but now I appreciate the 6sn7 (especially this old Raytheon) with the proper adapter. I've also been interested in upgrading caps, but haven't done so yet. I'm trying my hardest not to sink any more more into my BHC, as I might be getting a TOTL tube amp that I've really longed for, so I'm trying to show restraint!!

I don’t think there are any tubes I’ve tried I flat out didn’t like, it’s just some synergize better with others, which is what makes the tube rolling journey so fun IMO. That being said, nothing wrong with leaving it alone if it sounds good. It’s very hard to make the BHC sound bad!

What tube amp are you getting next?

 

[skhan007]

I don’t think there are any tubes I’ve tried I flat out didn’t like, it’s just some synergize better with others, which is what makes the tube rolling journey so fun IMO. That being said, nothing wrong with leaving it alone if it sounds good. It’s very hard to make the BHC sound bad!

What tube amp are you getting next?

I hope to get the LTA MZ3, which to date, is the best sounding tube amp I’ve ever experienced.

 

[cebuboy]

What bad news! But anyone with the same problem? or without it?

Did not experience any noise problems with the Garage 1217 6sn7 adapter.

 

[GreenNeedle]

I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.

After reading around a bit over the past year or more I wondered whether my green wiring from transformer to octal socket to noval socket was twisted tightly enough. I see some very tight twists on photos so that is one job I intend to do (have been intending to do this for over a year. lol)
There are also some comments about the proximity of a couple of the solders on the noval socket. Then of course there are the LEDs under the noval socket which might become a little weak when a little tight on the legs.

I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?

I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s. If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive. I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.

At what point on "the clock" is the zero marker at on yours? 3 'o' clock makes me think of instant deafness.

 

[skhan007]

Did not experience any noise problems with the Garage 1217 6sn7 adapter.

I was planning on purchasing the Garage 1217 adapter, but several on this thread advised against it, having had damage done to their amps as a direct result. I know that doesn't account for everyone, as there are many who didn't have problems with this adapter, but I didn't want to risk it and heeded the words of caution who had bad experiences with the Garage 1217. I bought the Xulingmrs adapter that was recommended.

My particular observation with my Xulingrmrs adapter: Very very slight hum with my Raytheon 6sn7; slightly more hum with my Sylvania chrome top 6sn7; unbearable and non-ignorable hum with my Sovtek 6sn7GT. The former produces a hum so slight, that it's only heard when there is no music playing. It's inaudible (but likely present) with any music playing.

I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?

I likely concur with this. I don't know enough about what is going on, however. At first, I thought it must be a grounding issue or perhaps an artifact of the tube itself. I wish I had a proper 6sn7 tube amp to test my tubes, to see if they hum in a different amp. Then, I would know it's definitely the adapter or the BHC.

 

[Dawgfish]

After reading around a bit over the past year or more I wondered whether my green wiring from transformer to octal socket to noval socket was twisted tightly enough. I see some very tight twists on photos so that is one job I intend to do (have been intending to do this for over a year. lol)
There are also some comments about the proximity of a couple of the solders on the noval socket. Then of course there are the LEDs under the noval socket which might become a little weak when a little tight on the legs.

I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?


At what point on "the clock" is the zero marker at on yours? 3 'o' clock makes me think of instant deafness.

I control the volume via the source not the amp. The source volume is turned down to moderate levels.

 

[MacMan31]

This is wayyy too much fun: Bifrost 2/64 -> Mullard 6080 + Telefunken G-73R -> ZMF Verite Closed

That is an amazing BHC. I had one a little while ago but sold it. I could never make one this awesome looking. If I knew someone that could I'd pay them for it. Where did you get the right angle headphone adapter?

 

[SHIMACM]

It could be the actual adapter. I went through 3 6sn7 adapters before I got one that didn’t have a hum. The good one was from Garage 1217. Though I was fine with my first 6f8g adapter. It is a bit weird that it happens for you with ANY adapter…

Well, it actually happens with all adapters.

The Garage adapter also read a lot of negative reviews about them.

And something to think about.

 

[SHIMACM]

Can anyone with Crack without Speedball installed, and who uses 6sn7 with adapter, can tell if they are having problems with noise or not?

I'm trying to understand if the speedball contributes to the noise production when using valves like 6sn7, 6j5g, 6f8g.

 

[pravous]

BHC with speedball here. I too had problems with noise with 6sn7 but found after I got a tester that they were very low testing 6sn7. I have zero issues with 6j/c5g.

 

[skeptic]

Can anyone with Crack without Speedball installed, and who uses 6sn7 with adapter, can tell if they are having problems with noise or not?

I'm trying to understand if the speedball contributes to the noise production when using valves like 6sn7, 6j5g, 6f8g.

It has been years, but you can add me to the list of those who tried multiple 6sn7 tube adapters and never managed to get one that didn't introduce significant noise. I eventually gave up on that avenue and added an early iteration of maxhawke's bias selector board to my crack. Been very happy with an amperex pq e80cc + 5998 ever since (other mods - TKD 2511 pot, 100uf Obbligato coupling caps, and psu choke). Candidly, I liked GEC 6as7g in the back even better than the 5998, but mine eventually died, and the cost of a replacement appears to be more than my Mainline lol. Hard pass.