So after running it for nearly six days straight I turned off the SEX let her cool down for the evening and then went upstairs to have a listen.
In keeping with my tradition of letting my Japanese friends nickname my amp projects the SEX has has now been named the Ton-O-Fun due to the sheer volume and weight of the caps I managed to shoehorn into it.
The current configuration of the TOF is as follows.
MQ Iron and C4s upgrade.
Shorting hedphone jack.
Replaced Parafeed cap with 2uf Russian PIO
Replaced the coupling cap with .1uf Russian PIO
Replaced Cpsu with a soup can sized Solen I had laying around
Replaced Cd_psU with some even bigger 24uf motor runs I dug out of the parts bin
The bias caps were replaced with 1000uf Nichicon Muze
The remaining Psu Caps were moved to the center of the amp to make room for the Cpsu and Cd_psu caps and wired back to the stock location with the shielded wire supplied with the kit.
And the heater cap was replaced with a 10000uf Mundorf Mlytic
All signal wire is Mundorf Silver/Gold 1mm with unbleached cotton tubing.
So how does it sound?
First I was amazed at how quite the amp is. Especially with all the unshielded signal wire. There is no audible hum through my headphones (AKG 204M) or through my speakers (96db Fostex Horns). This is the only amp I have that has zero hum.
Second I was amazed by the accuracy and the effortlessness this amp plays at. For instance on "Cavern" by Phish there are several passages that come in and out just slightly off beat. 99% of the amps I have listened to smear this in with the other transients going on and totally loose this into background noise.
This amp also images very well. In "Blues Music" by G Love the vocals are dead front center for most of the song except for a few brief moments when the singer was turning his head back and forth while singing. This often causes a pan effect especially when listening through headphones. With the TOF it sounded just like someone turning their head. Also the vocals are placed very far front with the upright base slightly further back and to the right and the drums even further back and very slightly left. The TOF was right on and gave a real sense of depth and spacial relation.
The next thing that amazed me was the bass. I normally wouldn't even dream of playing hip-hop through any of my tube gear. But after listening for a while I decided to give it a whirl as the bass seemed to extend to about 30hz with relative ease. So I threw on some Dr. Dre and gave it a whirl. The little TOF plowed through a couple songs of of "Chronic 2001" like a 17yr old's thumpin Honda Civic except that you could actually hear that the bass consisted of real notes. Determined to find the limit of the bass I then switched to some Techno that I new had bass below 20hz. Going off of memory of what tones were where in this piece I'm guessing that good old TOFy didn't start rolling off until about 26hz and was producing usable energy to about 18hz. Oh and it still sounded good through the rest of the frequency range maintaining separation and imaging the whole time.
Now I just need some speakers that this thing can drive. TOF does not like to play my horns to the volume levels that I like to listen at. My neighbors are probably happy about that, but I am not. Gonna throw the FE108EZs in a Frugal horn and see if the added efficiency as compared to the Fostex design gets me the headroom that I need. If not guess I will have to get something more efficient, probably go to something open baffle, hate to go to the active crossover and subs with this fellow. The bass it puts out sounds too good to offload.
I'll throw some pics in the gallery tomorrow of everything in its final form tomorrow. Its 1:30am here in Japan and I need to get to bed.
Be well
