Galen, something very odd just happened

Hi @rower30. So I wandered over to listen to my system (currently wired with Series I OFE on the lower and the Series II TPC on top - which Bob is kindly letting me hold on to until my audio buddies can finally make it over this coming weekend to listen). I sat there and said “WTF? There’s no low end,”. I played a number of tracks, using all my sources. Did the big red button reset on everything more than once. I even pulled out TrueRTA and ran some pink noise, measuring each channel individually. It was pretty definitive. I first thought the lowers on both my speakers were blown, but I don’t play any low frequency square wave type stuff, and never listen past about 80dBA anyway, so I figured that was unlikely. Then I thought both (!) of my Pass amps had their left hand binding post outputs open somehow (I use the left on each for the LF cables), but the Pass outputs are just paralleled hardwired from the output board. So also unlikely. But just for grins I measured the RMS voltage from both sets of outputs on both amps, using pink noise. They were all approximately equal.

I shut the amps down and on the left channel moved the OFE to the same posts being used by the Series II. Turned that amp back on. Everything was as it should be. So I took out the Fluke DMM and measured the resistance from the OFE on the right channel amp, from where they met the binding posts on the amp to where they met the binding posts on the speakers. The positive lead was open circuited. I loosened the binding posts on the amp, pulled those OFE ends, and gave them a bit of flex. Put them back on the same (their own) binding posts on that amp. Checked continuity. Suddenly all good. Turned on that amp. All good.

The likelihood that two of anything in an audio system should exhibit the same odd behavior - at the same time - is virtually impossible. But I have nothing else that is suggesting anything to me. My Series I OFEs are not the later build with the welded ends, if that might offer up anything. Things seem to be working fine now. :man_shrugging:

No, things are not right. :thinking: :expressionless: Even though the frequency range is back, the low end doesn’t sound like it did before. It’s incoherent, plodding. I put my other cables back in play, and while they were previously bested by the OFE I / TPC II combo, now the low end out of my speakers sounds like what my speakers are capable of doing.


Don’t you gate stuff like this? We can fully retest your leads at the shop, DCR, R, L and C and dielectric test. I don’t know what else we can do for the cable portion. But at least this is a start.

The end tech shouldn’t matter at all, WBT silver solder or ultra-sonic welds.

The amps terminals are parallel inside, yes, so switching the terminal is inconsequential to anything.

Let me know what you decide. We can have Bob Howard make the arrangements for you.


Okay. I have to send the Series II back next Monday anyway. Will it be too detrimental to the overall presentation if I just use the Series II for my friends? I know they are not ideally optimized for the low frequencies.


No not at all. The series I to series II are SLIGHTLY different DCR, and will make a small change to the voltage dropped across the two cable (voltage divider rule). But the AWG is still pretty hefty on both cables so that is a small worry as short as our cables are. The DCR was chosen for longer runs of 20-30 feet! Yep, I wanted to make sure we are OK for about all installations. For just 10 feet we’re well good to go.

For bi-amp / bi wire applications it isn’t cost effective to say to everyone to use the series II only. The data just doesn’t support it. Use the series I for the bass. We are optimizing the INDUCTANCE with the series I design, and it is the SAME value as the series II, about 0.08 uH/foot. The series I can reach that inductance and a lower DCR for less money than the series II that is optimized well above the bass frequencies.


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Thanks Galen. I’ll give it a try and see how it sounds.