Group Buy: MOVED TO NEW THREAD

Grumpy_Git · « **Reply #40 on:** 10 Jun 2008, 11:53 am »

n) They just sound "good" compared to the Orions but different.

Nick.

PT914 · « **Reply #41 on:** 10 Jun 2008, 03:14 pm »

Hi Aurelius,

#4. You don't need a reference system to hear these improvement. And even budget speakers are limited by the electronics.

Philip

aurelius · « **Reply #42 on:** 11 Jun 2008, 09:06 am »

Thanks Philip...

I have come to trust your ear and judgement over the years and am not sure I could come to terms with you recommending that a pair of paradigms could sound better to you than your Orions.

West, just so you know, I am a likely participant in a group buy if it all comes together.

AKSA · « **Reply #43 on:** 11 Jun 2008, 10:01 am »

Marcus,

A most senatorial comment......

I too have come to trust Philip's ears. I am confident they both glow yellow in the night, I really am......

Ciao,

Hugh

PT914 · « **Reply #44 on:** 11 Jun 2008, 08:26 pm »

Hugh,

That's funny. My ears and my whole body is yellow. It's a racial thing, you know. Not gold or glowing.

Cheers,
Philip

AKSA · « **Reply #45 on:** 11 Jun 2008, 10:50 pm »

Phil,

You are off to a good start!!

Glowing ears are icing on the cake!!

Could you send a picture of you deeply immersed in the listening process?

Hugh

RonR · « **Reply #46 on:** 13 Jun 2008, 10:55 pm »

All,

The next installment of the C4 / C7 testing is here.

I've just finished the 20uF Solen Vs 20uF Sonicap Gen1 + Gen2 Bypass tests at C7, and....
The Solens win!

There's not much to choose between them, but the Solens exhibited marginally tighter bass and slightly more natural midrange and highs. I added damping resistors to the bypasses, and even removed them altogether, but the Solens still sounded better in this position.

Meanwhile, I've moved the Sonicaps to C4, and hope to get testing under way tomorrow.

I'd like to test some of the AudioCap PPMFs that Hugh pointed out earlier in this thread, but I can only find them at Michael Percy, and my record of actually ordering anything from him is not good. If anyone has another source, please let me know.

Cheers,

Ron.

kyrill · « **Reply #47 on:** 14 Jun 2008, 08:28 am »

the solens are being used from the beginning? Did the Sonicap had its burn in time?

RonR · « **Reply #48 on:** 14 Jun 2008, 09:10 am »

Hi Kyrill,

The Sonicaps were new, so they were left for around 5-6 days playing FM radio through them.
These are the first non-platinum Sonicaps that I've tried, so I don't know the burn-in characteristics. Do they need longer than that? In my experience, film caps have a much shorter break-in period than Electrolytics.
I must admit it has me puzzled too, so when the C4 testing is complete, I'm going to re-test the Sonicaps at C7, to be sure I've not missed something.

So the order of testing is:

1. Sonicap Vs Solen at C4
2. BC560 at T4, and maybe T6?
3. Sonicap Vs Solen at C7 (again)
4. AudioCap PPMF Vs the others if I can get them.

Cheers,

Ron.

kyrill · « **Reply #49 on:** 14 Jun 2008, 09:15 am »

hi
100 hrs burn in is enough to get a good idea
Suppose the BC560 will sound better
is it easy to buy those things?

RonR · « **Reply #50 on:** 16 Jun 2008, 05:52 pm »

Kyrill,

BC560s are easy to get hold of, and they're a few pence each, so it's a bit of a "No brainer" if they work well.

I think Hugh uses Philips transistors in the GK-1 which are said to be the best sounding in a musical sense, but I haven't seen Philips BC560s, only other makes.

On the other hand, I have a few JFETs on hand for another project. Could this be an option, Hugh?

Cheers,

Ron.

AKSA · « **Reply #51 on:** 16 Jun 2008, 11:31 pm »

Hi Ron,

Our noise issue applies to the CCS, which is supported from the top (positive) rail. A BC557 is used as the active element here, so if a JFET is replaced it must be p type.

It could be done, and it might be cheaper, but the wiring is slightly different, with the gate returned to positive rail, a variable resistor of 100R between source and rail, and the drain taken to the collector of T3, the 'Output to Attenuator' connection.

You could replace T3 with an n type JFET although it will greatly affect the feedback factor and thus require re-engineering the compensation schema in the circuit, viz C3. If using n types, it would probably be best to use them in the diff pair, but again, their transconductance is far lower than bipolars and there will be draconian effect on the open loop gain.

It's all good stuff, isn't it?

Thanks for all the caps tasting ceremonies, Ron, it's quite a palaver isn't it? BTW, I've never used the non-teflon Sonicaps either, often wondered what they were like.....

Cheers,

Hugh

kyrill · « **Reply #52 on:** 17 Jun 2008, 08:55 am »

hi Ron

plz if you will, test silent transistors in the original topology

otherwise for ppl like me who barely could assemble
according to Hugh's "handout" it will become too cumbersome

RonR · « **Reply #53 on:** 20 Jun 2008, 01:14 pm »

Hi all,
Here's a short update on the Cap testing:

The Sonicaps are doing much better at C4 than they did at C7. But hold your horses, I've got some AudioCap PPMFs winging their way to me at the moment. The smallest I could find was 40uF/100V, but they're roughly the same physical size as the 20uF Solen and Sonicap.

I'll be testing the BC560s this weekend, while waiting for the AudioCaps.

Hugh, I'd be willing to try the JFETs as a further test if you're interested, I have 2SK117, 2N5460, 2SK170 and 2SJ74 on hand, but guidance will be required on the implementation of these.

Cheers,

Ron.

LM · « **Reply #54 on:** 21 Jun 2008, 05:30 am »

I've just had 24uF Solens added in at C4 and C7 and gathering some early impressions now. I'll actually post those impressions on the GK1 Platinum thread when I get my thoughts together as I had a TKD attenuator added at the same time so it is impossible to say exactly what changes out of the whole were due to the Solens. Nevertheless, even at this very early stage, seems like a big improvement so as someone else said, thanks Philip for discovering the secret.

DSK · « **Reply #55 on:** 21 Jun 2008, 07:09 am »

Quote from: LM on 21 Jun 2008, 05:30 am

I've just had 24uF Solens added in at C4 and C7 and gathering some early impressions now. I'll actually post those impressions on the GK1 Platinum thread when I get my thoughts together as I had a TKD attenuator added at the same time so it is impossible to say exactly what changes out of the whole were due to the Solens. Nevertheless, even at this very early stage, seems like a big improvement so as someone else said, thanks Philip for discovering the secret.

Unfortunately there is no way you'll be able to distinguish between attenuator and caps as to which provided what benefits, but in your shoes I probably would have added both at the same time as well. I've heard a few designers say that (after circuit design) the attenuator has the biggest impact on the sonics of a pre-amp. Based on what I heard when adding the TKD/S102's, then much later adding the teflons & BG's, I would have to agree.

kyrill · « **Reply #56 on:** 21 Jun 2008, 08:33 am »

hm
i don't have a volume controller ( that is how we call an attenuator in Dutch) just a single resistor, so this ought to sound best?

andyr · « **Reply #57 on:** 21 Jun 2008, 08:38 am »

Quote from: kyrill on 21 Jun 2008, 08:33 am

hm
i don't have a volume controller ( that is how we call an attenuator in Dutch) just a single resistor, so this ought to sound best?

Mmmm, so how do you cope with different output levels from different sources, kyrill?

Regards,

Andy

kyrill · « **Reply #58 on:** 21 Jun 2008, 08:50 am »

hi Andy

I use the preamp as an inbetween between my DEQX digital preamp and the poweramp
a maybe expensive alternative to Hugh's TLP to add
tube magic to the "sterile SS setup
however i also noticed that the GK-1 sounds much better with the burson audio buffer in front of it, so i have DEQX-->Burson buffer-->GK-1-->amp

andyr · « **Reply #59 on:** 21 Jun 2008, 09:08 am »

Quote from: kyrill on 21 Jun 2008, 08:50 am

hi Andy

I use the preamp as an inbetween between my DEQX digital preamp and the poweramp
a maybe expensive alternative to Hugh's TLP to add
tube magic to the "sterile SS setup
however i also noticed that the GK-1 sounds much better with the burson audio buffer in front of it, so i have DEQX-->Burson buffer-->GK-1-->amp

Aaah, thanks!

Regards,

Andy