[JamieMcC]

Look what turned up today... (Russian paper in oil caps). Not sure that they'll be better than the Auricaps I've been using, but interested to hear them...

This will be interesting I really liked them in my Crack they had a really engaging sound and bypassing with one of those small value Russian Teflons I thought helped the bottom and top end. The Pio do take a while burn in.
Looking forward to hearing how they work out

 

[Loquah]

This will be interesting I really liked them in my Crack they had a really engaging sound and bypassing with one of those small value Russian Teflons I thought helped the bottom and top end. The Pio do take a while burn in.
Looking forward to hearing how they work out

 
Just finished a temporary install (using screw terminals so I can switch back to the Auricaps later for comparison. It's obviously way too early to judge how the final sound might be, but amidst a slightly thick sound there are signs of some really engaging separation and texture to the sound. Much burn-in still required...

 

[Loquah]

   
Just finished a temporary install (using screw terminals so I can switch back to the Auricaps later for comparison. It's obviously way too early to judge how the final sound might be, but amidst a slightly thick sound there are signs of some really engaging separation and texture to the sound. Much burn-in still required...

 
Sorry for double post. I just wanted to record somewhere right away that my expectations are (probably incorrectly) biased towards the Auricaps. For some reason their combination of neater packaging, actual branding and new technology has me assuming the PIOs will come in a distant second. Looking forward to seeing if I'm wrong. For now, I've switched to the Sovtek tubes to waste some hours burning in playing games and leaving the amp running with music when I'm not using it

 

[Loquah]

JamieMcC, I just realised I have a pair of 1.5uF Mundorf SGOs in me SEX that is currently unused. From your experience with the PIOs do you think bypassing them with this Mundorfs would be a worthwhile exercise or too similar?

 

[JamieMcC]

JamieMcC, I just realised I have a pair of 1.5uF Mundorf SGOs in me SEX that is currently unused. From your experience with the PIOs do you think bypassing them with this Mundorfs would be a worthwhile exercise or too similar?

It only takes a couple of minuets to whip them out. But I would also get some cheep Teflons just to see how a inexpensive set up will compare to the expensive boutique caps

 

[Textfeud]

I just received the Bottlehead S.E.X. and boy does it sound great. I'm using it with my Zu speakers and ZMF Vibro. The Zu speakers are 16ohm so I believe I should put the amp on 16ohm right? And 16ohm is MH on hi and ML on lo if I'm not mistaken? I don't have a manual so can't check. Hope somebody hear knows for certain

 

[Loquah]

It only takes a couple of minuets to whip them out. But I would also get some cheep Teflons just to see how a inexpensive set up will compare to the expensive boutique caps

 
I can't find any 1uF teflons on eBay, only 0.1uF which is 1% rather than the 10% capacitance that is the rule of thumb (as I understand). What value caps did you use, Jamie?
 

  I just received the Bottlehead S.E.X. and boy does it sound great. I'm using it with my Zu speakers and ZMF Vibro. The Zu speakers are 16ohm so I believe I should put the amp on 16ohm right? And 16ohm is MH on hi and ML on lo if I'm not mistaken? I don't have a manual so can't check. Hope somebody hear knows for certain

 
It's OK to play around and see what sounds best - just make sure you switch the amp off before changing any settings. The BAL/UNBAL switch should ideally be in BAL (balanced) for speaker operation and in UNBAL for headphone operation (unless your headphones are connected to the speaker taps with an adapter cable). As for the impedance, play around with each impedance setting. A higher setting (i.e. 16 / 32ohm) may be preferable for the extra driving power. It will raise the noise floor slightly, but you probably won't hear it from speakers like you would from headphones. Here's the page explaining the impedance switches.
 

 

[Textfeud]

   
I can't find any 1uF teflons on eBay, only 0.1uF which is 1% rather than the 10% capacitance that is the rule of thumb (as I understand). What value caps did you use, Jamie?
 
 
It's OK to play around and see what sounds best - just make sure you switch the amp off before changing any settings. The BAL/UNBAL switch should ideally be in BAL (balanced) for speaker operation and in UNBAL for headphone operation (unless your headphones are connected to the speaker taps with an adapter cable). As for the impedance, play around with each impedance setting. A higher setting (i.e. 16 / 32ohm) may be preferable for the extra driving power. It will raise the noise floor slightly, but you probably won't hear it from speakers like you would from headphones. Here's the page explaining the impedance switches.
 

Thanks for the advice and the instructions! I like the 16ohm switch the best with both my ZMF Vibro and the Zu Soul Superfly. I felt the 32ohm gave too much noise and it had too much power for especially the ZMF Vibro. The 8ohm and 4ohm were just not powerful enough for the speakers. The 8ohm would have worked fine with the ZMF Vibro too, but I'm learning myself not to listen to headphones so loud anymore so that could be why. Anyway, I'm glad I like the 16ohm best for both the speakers and the headphone. I will go test balanced vs unbalanced for the speakers!

 

[JamieMcC]

   
I can't find any 1uF teflons on eBay, only 0.1uF which is 1% rather than the 10% capacitance that is the rule of thumb (as I understand). What value caps did you use, Jamie?

 
The 0.1uf worked fine in the Crack and worked wonders with the top end on my T1's. Just make sure the teflon capacitors chosen have the suitable voltage rating.

 

[Loquah]

   
The 0.1uf worked fine in the Crack and worked wonders with the top end on my T1's. Just make sure the teflon capacitors chosen have the suitable voltage rating.

OK, great. I'll give it a go. Cheers!

 

[Solarium]

Has anyone got experience pairing the Mainline with the Fostex TH-900?

 

[punit]

I have both. IMO they don't go well together.the Th900 sounds quite lacklustre compared to other amps.

 

[Loquah]

I got around today to rewiring the Mainline using the 0.1uF FT-3 teflon caps that were in the power regulator board as bypass caps for the Russian PIOs I installed recently (I re-fitted the standard Dayton caps on the power regulator board).
 
I'm not sure I'm really hearing any improvements from the bypass and by now all the caps in use are well burned in. On top of that I think the resolution and clarity of the Auricaps are preferable to the slightly thick sound of the PIOs. The PIOs do have a certain texture that's appealing, but the soundstage has compressed in width and the sound overall is just a bit too thick now I think. I might give this setup another day or two, but expect to be returning to the Auricaps pretty quickly now...

 

[skeptic]

I wonder how much of what you are hearing can be attributed to phase distortions caused by the bypass caps.  When I tried adding Russian teflons across the obbligatos in my crack, I liked the change at first but then became convinced over time that the sound was overall less clear and pulled them.  In hindsight, I am definitely happier with a good solitary coupling cap in each channel to avoid phase issues.  
 
Doug at ECP comments on this on one of his early diy blog entries: "The note here is that this made a world of difference. Bypassing causes its own phase distortions apart from the ones caused by the low pass filter, and whether bypassing is a good idea in a particular circuit depends whether the good done by the bypass cap outweights this harm."  http://diy.ecpaudio.com/p/some-notes-on-coupling-capacitors.html

 

[Loquah]

  I wonder how much of what you are hearing can be attributed to phase distortions caused by the bypass caps.  When I tried adding Russian teflons across the obbligatos in my crack, I liked the change at first but then became convinced over time that the sound was overall less clear and pulled them.  In hindsight, I am definitely happier with a good solitary coupling cap in each channel to avoid phase issues.  
 
Doug at ECP comments on this on one of his early diy blog entries: "The note here is that this made a world of difference. Bypassing causes its own phase distortions apart from the ones caused by the low pass filter, and whether bypassing is a good idea in a particular circuit depends whether the good done by the bypass cap outweights this harm."  http://diy.ecpaudio.com/p/some-notes-on-coupling-capacitors.html

 
You might be right as I think the sound might have been a touch better before the bypass. Either way, the Auricaps are still superior in the Mainline compared to the PIOs with or without the bypass. Thanks for the note though - very interesting