Parasound Halo JC-1 for Thiel CS 5i

Last week we had a very enjoyable day up in the mountains trying different things on Ed (Edgar)Krammer’s (reviewer for 6 moons, Australian hifi and Audio Esoterica) system which consists of an AMR CD-777 flagship CDP a pair of Parasound JC1’s and a pair of Wilson Alexia’s.

Preamps we had on hand were Supratek Grange, Nuforce all discrete flagship Reference P20, and a passive preamp.

All were used via the rca inputs on the JC1’s as we were only using 2mt interconnects and also didn’t want the extra circuitry of balanced inculded the signal path, as the AMR is tube output and TDA1541 convertor and therefore really single ended anyway even though I think it has token balanced outputs.

The one that came out on top was the passive, by quite a margin, for top to bottom transparency, dynamics, drive, and top (delicacy) to bottom (tight) extension.

The JC1’s controlled those hard to drive Alexia’s like they were born for it, with the extended Class A switched to on they were delicate, sweet and extended when needed, holographic midrange with real body to it, and controlled slamming subterranean bass to the depths of the earth.

.Cheers George

Yes I know, that was a tongue in cheek question mark, with eyebrows raised.

Let’s just say I like Class D for >4ohm bass/sub duty)

Cheers George

No I don’t, wish I could, in Australia they are over $18k. And to buy a s/h pair in the US is cheap enough, but shipping for me is a huge cost, and then I’d need to convert them to 240v, but this could be just a primary transformer tap change if lucky.

I have something similar two pairs of ME850’s (long out of production) but very similar topology to the JC1’s.

My reviewer friend Edgar Karmer for HiFi Australia, 6Moons, and who also owns Audio Esoterica magazine has a pair of JC1's, and they were the best thing (beside an ME1500 also out of production) we found from many to drive his Wilson Alexia’s with, which are also a bitch to drive.

Cheers George

dsper Hi, Well, here is the latest on the great experiment with the Parasound A21.

At 11 o’clock on the preamp while playing Fleetwood Mac "Rumors", the A21 one started to clip and went into protection mode.

I routinely run the W4S ST1000 at 2 o’clock with no problem.

The answer is 400 watts into 4 ohms is not going to cut it with the Thiel CS 5i’s.

Any other suggestions beside the Parasound JC1’s?

Dsper

Dsper

Input Sensitivities.

Parasound A21 =1v

WFS ST1000 =2.95v (yours)

WFS ST1000 mkII = 1.31v

These are the input voltages needed into to make each amp reach it’s maximum output (watts) before distorting or shutting down or blowing up.

Now you can look back at your 11 o’clock and 2 o’clock preamp statements and see what’s happening.

And as I said the A21 will drive them but the JC1’s are the real deal, as for the WFS it’s class D, ?

Cheers George

That A21 should be fine as well, not as good as the JC1 monoblocks but should do the trick.

As it is also a JC design with bi-polar (BJT) output stage, which should give good current ability as well.

As for the A31 adding power from the third to the two channels if the third is not used?????? (bit of sales bulls**t there) I think this is just a powersupply taxing thing not a bridging thing, as how can a signal channel be split to add to two separate channels???? (It can’t)

I’d stick to the A21, if you can’t afford or get the JC1’s.

Cheers George

I agree stupid money, but what I’m sort of getting across is the JC1’s are maybe just as good (with more watts) and I’ve seen them for $3k for a ruff pair, these are $4k. in Australia they are around $16K

https://www.audiogon.com/listings/solid-state-parasound-halo-jc-1-monoblock-amps-pair-no-paypal-fee-price-reduced-2015-12-29-amplifiers-85224-chandler-az

Cheers George

Here is a great new amp from Accuphase if you can afford it, that will drive those Theil’s without breaking a sweat. Not as cheap or as high wattage as the JC1’s but just as brutal with it’s ability to drive low impedances.

"Accuphase’s head of engineering, Masaomi Suzuki, introduced the company’s new P-7300 flagship class-A/B stereo power amplifier ($32,000). The amp outputs 125Wpc into 8 ohms. Its versatility extends to outputting 800Wpc into 1 ohm, which means that loudspeakers with challenging, amp-wilting impedance curves should not present insurmountable problems."

http://www.stereophile.com/content/all-way-accuphase-and-gauder-akustik

Cheers George

dsper

The W4S is rated at 40 amps. I also see that an older Krell FPB 300c was rated less than that.

Something is very wrong with what you saw or read, as there is no way the W4S could out current the Krell FPB 300c, especially into 4-2ohm loads, where it counts with the OP’s speakers.

Where did you see this? If these were figures can you point to them?

I would hazard a guess that one was "peak" amps and the other was "rms" amps at the very least.

PS: As the next Krell up "350c" I found can do
" Specified power is 350Wpc into 8 ohms, 700 big ones into 4, and a whopping 1400W into punishing 2 ohm loads."

These sorts of figures indicate massive current/amperage, and the 600c is much more. The WFS has no chance of doing these sort of figures.

PPS: I did find these figure on the 600c

Driven on a toneburst equivalent to peak program duty at 8 ohms, it reached to touch the 1000W line, while at 4 ohms it attained 1850W, and for 2 ohms 3530W. And for 1 ohm—wait for it—an amazing 6000W!

Cheers George

Now that I’ve seen the impedance graph of the CS5i, I would say forget the WFS and go with the JC1’s.

"Sensitivity: 87dB/2.83V/1m (equivalent to around 82dB/W/m, given the low impedance)".

I didn’t realize the CS5i is so low in impedance in the bass and lower bass, below 2ohms, Class D will not drive this as well as the JC1’s

http://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements-0#TU8p8MtO6awD64KO.97

Cheers George

I believe yes, in the upper mids and highs.

Class D will equal or can even better in the bass or low bass, but from mids up the JC1's especially with the higher bias Class A switch on, should be far better that the ClassD, for these reason here I posted.

 https://forum.audiogon.com/posts/1267957

Cheers George