"Hazen" Mod on Simple SE?

[Davec113]

Many hours of run time at this point, it is working fine. I really think this mod along with bypassing the power tube's electrolytic cathode cap has made a decent to large improvement in the SSE. There is significantly less distortion and a corresponding amount of detail has been revealed. The amp is also smoother, more dynamic, and easier to listen to.

[GanzerD]

Before I get started... I'm a newbie....The SSE is my first Tube amp, so my comments should be taken with that in mind.....
My SSE is a very pedestrian build. Edcor transformeres and choke GXSE15 OPT's, a 5U4 rectifier and EL34's....

I tried this mod (hazen) and the cathode cap bypass cap this weekend.
One of the things that really struck me when I first started listening to the SSE was how defined (for want of a better word) the performers positions were. I could almost see the position in space of the performers....It was a revelation to a newbie!
The downside was that the highs were a little "hot"....Not quite balanced with the rest of the audio spectrum.
After these mods the amp sounds better balanced. The highs, that were a bit shrill, are now very "smooth" .
There does seem to be a downside though.... Now it seems that the phase relationships drift around. I mean, the performers placement moves around slowly. It's a bit disconcerting after the very tightly defined feeling I had initially.
Does any of this make sense to anyone? or am I imagining it all? I'm so new to this that it's very possible.....
FWIW
Dave Ganzer

[Davec113]

Originally Posted by GanzerD

Before I get started... I'm a newbie....The SSE is my first Tube amp, so my comments should be taken with that in mind.....
My SSE is a very pedestrian build. Edcor transformeres and choke GXSE15 OPT's, a 5U4 rectifier and EL34's....

I tried this mod (hazen) and the cathode cap bypass cap this weekend.
One of the things that really struck me when I first started listening to the SSE was how defined (for want of a better word) the performers positions were. I could almost see the position in space of the performers....It was a revelation to a newbie!
The downside was that the highs were a little "hot"....Not quite balanced with the rest of the audio spectrum.
After these mods the amp sounds better balanced. The highs, that were a bit shrill, are now very "smooth" .
There does seem to be a downside though.... Now it seems that the phase relationships drift around. I mean, the performers placement moves around slowly. It's a bit disconcerting after the very tightly defined feeling I had initially.
Does any of this make sense to anyone? or am I imagining it all? I'm so new to this that it's very possible.....
FWIW
Dave Ganzer

Yes, I noticed the improvement in the highs with the cathode cap bypass cap added and an overall improvement in clarity with the Hazen mod. I have not noticed a change in soundstaging, I am running Omega Super 5 XRS speakers which are 5" single drivers, imaging and soundstage are their strong point. These mods didn't change the overall sound of the amp either, just cleaned it up a bit... Back to the soundstage, I think this is mostly a product of the mastering of the source material but is certainly affected by the amp... unfortunately I have no idea how the bypass caps or Hazen mod might have affected this, in my case I didn't notice a change. Did you do both mods at the same time? If not it would be interesting to hear which mod caused your change in imaging.

[GanzerD]

Originally Posted by Davec113

Yes, I noticed the improvement in the highs with the cathode cap bypass cap added and an overall improvement in clarity with the Hazen mod. I have not noticed a change in soundstaging, I am running Omega Super 5 XRS speakers which are 5" single drivers, imaging and soundstage are their strong point. These mods didn't change the overall sound of the amp either, just cleaned it up a bit... Back to the soundstage, I think this is mostly a product of the mastering of the source material but is certainly affected by the amp... unfortunately I have no idea how the bypass caps or Hazen mod might have affected this, in my case I didn't notice a change. Did you do both mods at the same time? If not it would be interesting to hear which mod caused your change in imaging.

Unfortunately I did both changes at the same time.....I've never been a good scientist....
DaveG

[Davec113]

I had a couple thoughts... one, let your new caps burn in for a while and see what changes. If you still think the imaging isn't stable after a while maybe try bypass or Hazen mod caps that are larger in value, it could be the frequency of the music affected by the caps is falling in a range that's having an effect on imaging. My guess is it's the cathode bypass caps that are causing the problem, if the bypass cap's effect falls of to the electrolytic in the wrong freq range the difference in esr between the 2 caps might cause phase shift, IDK... just a theory. Makes me want to try a larger value bypass cap, maybe 1-3 uF in stead of 0.1...

For me, the Hazen mod had a noticeable effect on the bass and lower freqs, so I'm less likely to think that's the problem, and I haven't read reports of this happening with other people that tried the Hazen mod.

I'm going to look into options on how to eliminate the cathode caps altogether.

After my experiences with replacing the c2 electrolytic with a film cap as well as bypassing the cathode cap I am starting to realize that electrolytic caps are best avoided altogether, even in the power supply. Replacing c2 improved dynamics and removed another layer of "grunge" likely caused by the electrolytic. It was the cathode bypass cap that smoothed out the harsh high frequencies, which is an often stated audio characteristic of electrolytic caps.

[Davec113]

I just want to report back that in my case, imaging is unaffected and as normal with the SSE, it is rock solid and multi-dimensional.

Next, I am thinking I can get away with simply removing the cathode caps in the driver stage...