[ronpod]

I have been enjoying my C2 for a couple of years. However the left channel speaker has been slightly muted. I isolated the slight decrease in loudness to the Cornet2 by swapping cables between channels and eliminating everything else in the system. So today was the day to load up the C2 and all the other necessary stuff for an outing at the electronics lab at work. I connected the C2 to an Agilent signal generator putting out a 1k sine wave and ran a couple of probes (one for each channel) to a couple of channels on an oscilloscope. Comparing the output signals directly, the right channel had slightly more amplitude and was slightly ahead in time of the left channel. Only a funny capacitor would change the time between channels like that but which one? So I started comparing the signal path oscope traces from each channel. Everything looked identical through V200 into the grid of V201. However at the collector of V201 the signals diverged and maintained that divergence to the output. So something was amiss in the circuit between the collector of V201 and the grid of V202. Only one cap in that circuit; C204 a 1nF. I had a wild idea which I would not recommend for others to try; I clipped a jumper from between C204 and R213 from the left channel to the right channel. On power up the output signal was back to normal indicated by the traces overlaying each other on the oscope. So something was wrong with C204 and I removed both of them. It was very odd that they both registered as 1pF on the LCZ meter. These small Sonicaps are marked as .001uF at 600V. The reading of 1pF on the LCZ meter is strange for these caps. I replaced them with another pair that I matched on the LCZ reading 1nF. This corrected the problem and all traces from different points on the signal path were now identical.

The sonic character of the C2 is now a little different. The very low rumble caused by the needle in the vinyl record is gone. The high frequencies are also slightly less accentuated. Maybe the new components need to be burned in?
The left channel now sounds equal in loudness to the right and the music sounds more neutral. I will be listening more to understand these new changes.

Cheers,
ronpod

[poty]

... the left channel speaker has been slightly muted.
... the right channel had slightly more amplitude and was slightly ahead in time of the left channel. Only a funny capacitor would change the time between channels like that...
... I removed both of them. It was very odd that they both registered as 1pF on the LCZ meter. These small Sonicaps are marked as .001uF at 600V....
... I replaced them with another pair that I matched on the LCZ reading 1nF. This corrected the problem...

Hmmm... It's strange that having problem in two channels you hear the problem in one!
Speaking about 1pF instead of 1nF - it seems both capacitors has internal or external break (the lead(-s) is (are) doesn't (don't) have contact(-s) with the condenser armature). It could be defective goods or maybe the result of inappropriate mechanical or electrical influence.

[ronpod]

poty,

I strongly believe that one of the caps failed open while in circuit and the second one was working but I destroy it during extraction. So then they both measured poorly on the LCZ meter. I replaced them with little tiny 1nF caps that are not rated at the proper voltage so they are not likely to play well either. Replacement Sonicaps rated at 600 volts are on their way right now. I will replace the tiny caps with the good GenI's when they arrive in a couple of days. Hopefully the joy will return then...

[ronpod]

The four Sonicaps that I ordered arrived. I measured each of them on the LCR meter and selected two that were the closest in value. They are now in the Cornet2 and burn in has commenced. Both channels sound even and the sound stage is recomposed. Next will be to realign the TT cartridge to proper azimith. It is so nice having the Cornet2 and the Clarinet providing luscious vinyl sound to the Linkwitz Orion 3.2.1 speakers. This combination provides music that compares well to any of the systems that I heard at the RMAF a couple of weeks ago.

[ronpod]

It's been over a month since I replaced C204 in both right and left channels of the Cornet2. I thought the Sonicaps (Gen1) woul likely be a reasonable replacement in this RIAA circuit position. This cap does influence the frequency response of the whole system to an extraordinary extent. Just after replacement of the cap, the vinyl-analog chain of my system seemed restrained with poor high and low frequency reproduction. It took some time and patience to allow the cap to do whatever they must for the responses to return. But now I have been listening to vinyl this afternoon and the beautiful sound is back. So now the analog chain beats the digital chain once again but it sure is getting closer (hi res digital is getting very good). But the combination of vinyl and tubes still has that magic. The John Lee Hooker, "It serve you right to suffer" on Impulse is sounding sooo goood!