Other Stuff => Archived Manufacturer Circles => Herbie's Audio Lab => Topic started by: Nels Ferre on 2 Aug 2009, 12:34 am

Title: An Interesting Observation
Post by: Nels Ferre on 2 Aug 2009, 12:34 am
I thought you might find tis interesting. My Juicy Music Peach preamplifier always made a high pitched "ting" sound when switching inputs or switching from stereo to mono.

I just changed the main 6H30 tube from the stock EH to a NOS Russian military 6H30DR. An expensive gamble, but it really paid off. I really love the preamp with the DR. I highly doubt I'll ever sell it.
In any event, another member was selling a pair of the 12AX7 Tube Dampers, and I figured "What the hell." I was originally going to try them on my power amp, but decided to see if one would fit the 6H30DR, which it did. The "ting" which Mark Deeneen says is from the Peach being a zero negative feedback design, isn't entirely gone, but is greatly reduced. The amplitude of the "ting" did not change when I swapped tubes.

Has the sound improved with Herbie's Tube damper? I'm not sure because the 6H30DR is still breaking in, but I am certainly having fun. I can remove the damper in a few weeks and report back if anyone is interested.

The other damper is on the NOS LM Ericsson 2C51 in my MDDT Labs Havana DAC.

In any event, Herbie's Tube Dampers work!

Title: Re: An Interesting Observation
Post by: Herbie on 2 Aug 2009, 02:11 am
Hi, Nels. All of Herbie's tube dampers, assuming you have the right size, work with 12AX7 tubes. Some dampers though, like MidFi+, BlackBery, and original Teflon HAL-Os, are most appropriate for cooler-running small signal tubes only, like 12AX7, 6922 (and 2C51). There is some chance the isolation pads might not hold up well over the years if used with extremely hot-running tubes (rectifier, power, and 6H30 "supertube").

Depending somewhat on the component design, 6H30 tubes tend to run extremely hot, very hot like power tubes. For 6H30 tubes, I recommend UltraSonic or UltraSonic Rx Damping Instruments to handle the heat and assure top-quality results for the long haul. Lots of people are using them on 6H30s and enjoying considerable sonic improvement.

I don't know what kind of damper you're using on the 6H30DR, but sure, I'd like to hear about your results after break-in.

Herbie's Audio Lab (
Title: Re: An Interesting Observation
Post by: Nels Ferre on 2 Aug 2009, 02:16 pm

You are not kidding about 6H30's running hot. I haven't measured the temperature, but I would not be surprised if the 6H30 ran hotter than the KT88s my power amp uses.

I thought of the heat issue as well. From looking at your site, it appears that I have pair of UltraSonic dampers.

Thanks for pointing that out.