Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › The Stax Thread III
New Posts  All Forums:Forum Nav:

The Stax Thread III - Page 165

post #2461 of 5140

He's probably better off with the 007t than the 323s though they still need more amp; lesser of two evils.

post #2462 of 5140
Quote:
Originally Posted by milosz View Post
 

Frank

 

Couple things I'd like your opinion on-

 

Have you found that using a film cap  as the last cap in the PSU is sufficient, or do you need to replace all the electrolytics with film?

 

I've seen quite a few designs where the aluminum electrolytics in the PSU  and the on-board "demand" electrolytics in solid state amps are bypassed with one or two film caps- does that ameliorate the sonic problems caused by electrolytics or is it just wishful thinking?

 

And last but not least-  Black Gates are gone, but there are now other "audio grade" electrolytics - Silmic & Cerafine from Elna, and Muse from Nichicon - have you heard  these? Do you think they offer sonic benefit over the regular good quality but otherwise garden-variety Panasonic caps?


All right, one last go at the  electrolytic/film capacitor "debate" and then  I'll forever shut up about it. And to keep jcx happy, I freely admit that all my experience in this area is empirical and annecdotal.

 

My response to the first question is that the last cap in the PSU, which is directly in the audio path, is by far the most affected by upgrading an electrolytic to a film cap. When I first started building SET amps in the early 90's I made numerous direct comparisons (usually with simple "brute-force" supplies) of the two types in this position. The difference was easy to hear, and the film cap was always the winner. You could also hear it (to a lesser degree) in a push-pull, zero feedback DHT amp. Since then, since all my amps are DIY,  and I'm not concerned about space or economy issues, I usually use film caps in all positions. Probably doesn't make much difference as long as the last one is film.

 

I've never experimented with using film caps as electrolytic bypasses. I've read mixed results about the effectiveness of film bypasses

 

I've used all the brands of electrolytics you mentioned. I can't tell any difference between them and decent "garden-variety" electrolytics. Black Gates (and perhaps it was just  my aching wallet talking)  seemed to have a bit less of the usual "glare" or "sheen" that I associate with electrolytics.

 

Again to be clear, I am not criticizing any commercial product or designer for using electrolytics. If I was a commercial builder I'd use them too.There's really no choice. As a DIYer I am free to choose any capacitors I want, and I choose film whenever possible..

post #2463 of 5140

Thanks FrankCooter and jcx, in alphabetical order, for sharing your knowledge. This post in Tube CAD Journal was my previous knowledge about the subject and you both helped to fill some blanks in my mind. There is no conclusion without thesis and antithesis. I wish we had more of such debates here.

post #2464 of 5140

Last line of questions, and thanks for the replies.

 

Does the SRE 725  extension detract from SQ at all?  Are there any other makers of extension cables?  

 

Thanks again.

post #2465 of 5140
Quote:
Originally Posted by FrankCooter View Post
 


All right, one last go at the  electrolytic/film capacitor "debate" and then  I'll forever shut up about it. And to keep jcx happy, I freely admit that all my experience in this area is empirical and annecdotal.

 

My response to the first question is that the last cap in the PSU, which is directly in the audio path, is by far the most affected by upgrading an electrolytic to a film cap. When I first started building SET amps in the early 90's I made numerous direct comparisons (usually with simple "brute-force" supplies) of the two types in this position. The difference was easy to hear, and the film cap was always the winner. You could also hear it (to a lesser degree) in a push-pull, zero feedback DHT amp. Since then, since all my amps are DIY,  and I'm not concerned about space or economy issues, I usually use film caps in all positions. Probably doesn't make much difference as long as the last one is film.

 

I've never experimented with using film caps as electrolytic bypasses. I've read mixed results about the effectiveness of film bypasses

 

I've used all the brands of electrolytics you mentioned. I can't tell any difference between them and decent "garden-variety" electrolytics. Black Gates (and perhaps it was just  my aching wallet talking)  seemed to have a bit less of the usual "glare" or "sheen" that I associate with electrolytics.

 

Again to be clear, I am not criticizing any commercial product or designer for using electrolytics. If I was a commercial builder I'd use them too.There's really no choice. As a DIYer I am free to choose any capacitors I want, and I choose film whenever possible..

 

Thank you sir.

 

The only gear I've ever used which had all film caps was a Conrad Johnson PV10. All film caps in the PSU, except for the filament supply.  It was a nice sounding preamp, measured well too but I don't know how much of the good sound came from the PSU film filter caps.  I had a C-J PV7, it used electrolytics in the PSU, it sounded good to me, too.



This topic isn't SPECIFICALLY Stax-related, except that a few folks DO build their own amps for Stax, and if they are doing so they need food for thought; if ANYTHING is going to allow one to hear minute improvements in sound, seems to me it would be a pair of Stax 'phones, and so when doing a DIY tube electrostatic amp  it might well make sense to consider the use of film caps in the PSU. 

post #2466 of 5140

Don't worry about the cables.

Headphones > amplifiers > everything else

post #2467 of 5140

Yes, but I'd add a few more '>'s between headphones and amplifiers :wink_face:

 

Nice amp Tyll!  I think I have the same DC supply laying around and wanted to use it for the same application.  I'm going to guess that most Lambdas through the years measure very similarly in FR and maybe a little differently in square waves.

post #2468 of 5140

Hi Folks,

 

how do I measure the bias voltage at the output of my SRD box?

 

A Standar multimeter ? set to DC? between which pins?

 

 

Also what happens if you run a pair of ELS headphones at too high or too low a bias voltage?

 

thanks

post #2469 of 5140
You cant use an ordinary multimeter (maybe you can if you know the resistance of the multimeter and the layout of the srd).
Too high bias = not good
Too low bias = okay
post #2470 of 5140
Just got a pair of new 007Mk2 . They're even the dreaded sz3's. I know it's usually "Mk1's or go home" around here, but these are actually a very fine headphone in their own right. Compared to my 507's they have more depth, resolution, and better imaging. And though they may be a bit bright on top compared to the Mk1's (which I've heard many times), they are nowhwere near the 507's in this area. Many of the Mk1's I see at meets are starting to show their age. I passed on a couple of used ones. With the kind of electronics I use, (NOS dac, all tube DIY amp) a little extra energy on top and a hint of bass bloom might even be a good thing. On all-tube amps, the Mk1's, to me at least, can sound a little remote. I'm actually a bit surprised and pleased, as no way could I ever afford an 009. The three previous Lambda's I've owned have never really meshed with my tastes in music (mostly classic rock) or electronics (analog / tube). These pull it off. Definitely worth a look.
post #2471 of 5140

Congrats Frank.

Your stunning amps make any Stax sing. 

post #2472 of 5140

I thought one could get an idea of whether the Bias is in the right ballpark by measuring between Ground and the final 5M load resistor (ie not at the headphone pinouts)?

 

I am trying to both check the Bias and adjust the unit to run on 240V as it is a 100V only Vintage Japanese SRD7. - It is also a very early one, as the circuit is not the later SRD7 circuit but a slightly modified SRD5 circuit....

 

I have fitted the 250k resistor (replacing the 50k resistor, actually a 270K R as the local electronics store was out of 250k's would like to confirm what would be the ideal R for this position given local power voltage is 240V but tends to be 245V on average, and sometimes as high as 252V) - as per the SRD5 240V switch position....

 

But right now I still have it running on 110V - and have measured 70V before the load resistor.

 

 

At the pinouts I measure 47V.

 

I expect that when I switch to 240V the V just before the 5M resistor should jump up to around 154V - and based on other peoples measurements (using Multimeters) of bias voltages I have a feeling that this is right in the ballpark given the limitations of a 10M impedance DMM.....

 

Looking for some form of confirmation.

 

Also if anyone could chime in with what would be the ideal R for that initial power input resistor that would be great!

 

Is optimal performance achieved with the standard spec 230V bias, or is there a gain from running marginally higher bias? And if so what are the safe limitations for long term life of the headphones?

 

It seems I may be able to "tune" the bias by selecting the right input R...

 

thanks

 

David

post #2473 of 5140
Hi Frank
What NOS DAC have you got?

I endorse your point about the 007s Mk2.5. I had a pair for 12 months and loved them with my Audio Note NOS DAC front end.
They get slated here, I believe too much IMHO. With a balanced system (components that gel together) I think they offer one of the best headphone set ups available. Yes, the bass is slightly bloomy maybe? And the mid to high treble slightly recessed. I did not feel it was loosing much information or enjoyments regardless. In fact I would say the 007s are a better match for many modern SS DACs.

I have now got some 009s which are quite a different signature, more 507 on steroids than a development of the 007s. The 009s have a wider soundstage, more detail and about the same bass as the 007s but more texture and a bit more low end response and slam. The increased detail of the 009s takes the experience to a higher level and a more realistic level I would say, but to do that successfully I think the 009s need a clean front end even more than the 007s do. No where to hide comes to mind.

I'll know more on that once I get my KGSSHV built. I kinda miss my 007s right now, but it is not financially possible to keep both for me, and the 009s just give me more music. There is no denying the 007s signature though, it also has it's merits.
post #2474 of 5140

Right now I'm using an Audio Note 2.1B kit dac. I just purchased a used Metrum Hex. Should be here in a few days. Been on an upgrade binge recently due to cleaning out years of accumulated  tubes and components. The real fun will began when my best effort at a Stax system will go head-to-head with my best effort at an LCD-3 system. In the end, only one will stay.

 

Your impressions of the 507's and 009's mirror my own. My favorite Stax has always been the original Omega. Wished they'd taken the 009 more in this direction.

 

Greetings Gilency! Appreciate the complement! Hope to see you in August at the LA meet with your Megatron.

post #2475 of 5140

I'm looking for your comparison between the AN and Hex ;)

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: High-end Audio Forum
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › The Stax Thread III