The Headcase Stax thread

[deepak]

Have I been here long enough to do the same here? \

Go for it.

[cclragnarok]

Go for it.

Done.

[dc]

Say I've got an SRM-1/MK-2, what's the step up to the SRM-717 like?

Is it a worthwhile upgrade, if any? Or should I shoot for something like a used KGSS?

[spritzer]

Say I've got an SRM-1/MK-2, what's the step up to the SRM-717 like?

Is it a worthwhile upgrade, if any? Or should I shoot for something like a used KGSS?

It's an upgrade, that's for sure but how much really depends on what version of the SRM-1 you've got as the difference between an early A model and a late C model is substantial. It's been too long since I've had a 717 here but it's a great amp but the KGSS is even better...

[grawk]

What would be the best cheap solution to powering the esp950s?

[n_maher]

What would be the best cheap solution to powering the esp950s?

I'm guessing a SRD7 Pro or MKII, much like deepak is looking for. Not sure how often they come up and you've definitely got a bit of competition looking for one but still they seem to stay in the $200/$250 ballpark. I hope to be able to give some listening impressions later this week of that exact setup. Also, have a look at this list for models that have the pro-bias option, you may find a smaller solid state driver unit that wouldn't require a speaker amp.

[dc]

It's an upgrade, that's for sure but how much really depends on what version of the SRM-1 you've got as the difference between an early A model and a late C model is substantial. It's been too long since I've had a 717 here but it's a great amp but the KGSS is even better...

The serial on mine is A8921 so I guess that makes it an A model?

[spritzer]

What would be the best cheap solution to powering the esp950s?

An normal bias SRD-7 with a DIY SRD-7 Mk2 bias supply installed.

The serial on mine is A8921 so I guess that makes it an A model?

That's a late production A model.

[luvdunhill]

Spritzer:

any recommendation on cheap trafos for the DIY option?

[deepak]

An normal bias SRD-7 with a DIY SRD-7 Mk2 bias supply installed.

How easy is this to DIY? And will it fit in my SRD7-sb box?

[spritzer]

Spritzer:

any recommendation on cheap trafos for the DIY option?

The Just real music trafos would be an unseen recommendation but just about any 5000:8ohm output transformer with a CT primary will do the job just fine.

How easy is this to DIY? And will it fit in my SRD7-sb box?

The circuit can be made to be really tiny so it shouldn't be a problem. There were two versions of the SB design, one with extra transformer and one without but I've seen the service manual for the Mk2 SB model and it uses an identical bias supply to the AC powered unit.

[grawk]

An normal bias SRD-7 with a DIY SRD-7 Mk2 bias supply installed.

Ok, the hunt begins.

[luvdunhill]

grawk:

I'd strongly recommend something with a higher bias for the Koss. If you find a SRD-7 I'd consider doing the modification for you, as it would give me a chance to design a little board that might fit in there for future retrofits.

Spritzer:

I'd be interested in the cost on those transformers, at least.

[grawk]

grawk:

I'd strongly recommend something with a higher bias for the Koss. If you find a SRD-7 I'd consider doing the modification for you, as it would give me a chance to design a little board that might fit in there for future retrofits.

I'll take you up on that

If you can mod an srd-7 to 620v for me, that'd be great, and I'd probably actually mail off your lemos

Actually, those are going out this week, I promise

[spritzer]

Spritzer:

I'd be interested in the cost on those transformers, at least.

You can find them here. I also looked through the PCX site and Hammond 1608 output trafo should do quite nicely and gives a nice range of stepup ratios.

[Dusty Chalk]

Ok, the hunt begins.

I have a SRD-7 (non-pro-bias) that I'm not using.

[grawk]

cool, I'll be in touch

[GPH]

I received my SRM-T1S today.

First impression, that thing is huge compared to the SRM-Xh. With my Lambda Signature, the sound seems a lot fuller, especially bass, and spatial imaging is better, less diffuse. It also corrects partially the thinness in the lower treble, it's less harsh and the impact is smoother. I did some A/B comparisons today and it is better than the SRM-Xh in every possible aspect, but I kind of expected that considering the price difference (150$ vs 600$). There's probably a bit of new toy syndrome in what I say right now, but it's pretty easy to hear the differences between the two amps.

[catscratch]

O2 MkII on the way, ETA: Thursday.

SRD-7 Pro already here, and making the SR-003 sound better than it ever did on anything ever, together with a Dared VP-20 giving it some muscle.

Updated source coming sometime next week.

Man, sometimes this hobby can be very good!

[dc]

SR-Lambdas arrived this morning.

Plugged them in and let them charge while I'm at work.

When I get home they should be nicely charged up and ready to go

[Smeggy]

O2 MkII on the way, ETA: Thursday.

SRD-7 Pro already here, and making the SR-003 sound better than it ever did on anything ever, together with a Dared VP-20 giving it some muscle.

Updated source coming sometime next week.

Man, sometimes this hobby can be very good!

Sweet, another lucky bastard O2 owner. As jealous as I may be, I hope you enjoy them.

...bastard

[dc]

Have been listening to the SR-Lambda standard bias for the last hour or so.

Impressions so far compared to the SR-404 are a less detailed sound overall.

I remember going from the Lambda pro to the SR-404 and loving how less fatiguing it was. The upper mids were smoothed out and less peaky but not at the expense of detail or impact, if anything the SR-404 was superior in both regards.

Comparing the SR-404 and SR-Lambda side by side, the Lambda is relative to the SR-404 as the SR-404 was to the Lambda Pro, but unfortunately at the expense of detail and impact.

However, this makes it a more relaxed listen and better for background listening. On the other hand, I consider the Lambda pro and even the SR-404 a more engaging listen, I could not use them for background listening.

Sound quality aside, this pair are in great condition, and I'm surprised such an old phone has lasted this long. I think the headband is smaller on the Lambda compared to the Lambda pro and SR-404 though, since I have a large-ish head and have maxed out the headband on it, whereas with the SR-404 and Pros there is still a fair bit of room to spare.

[darkless]

Is it possible to let a 'stat charge up on one amp and then quickly unplug it and plug it into another amp with the phone keeping its charge?

I ask this partly because I want to know if it's possible to A/B 'stat amps using the same phone, and partly because many tube amps are quite taxing on the power bill, so using an efficient SS amp for keeping the phone charged might save some money over time.

[dc]

I think Spritzer does something similar, but in his headphone cupboard.

IIRC He has an always on bias line that keeps the stators charged.

And now, the progression of Stax's Lambda style earspeakers through the years:

[spritzer]

Is it possible to let a 'stat charge up on one amp and then quickly unplug it and plug it into another amp with the phone keeping its charge?

I ask this partly because I want to know if it's possible to A/B 'stat amps using the same phone, and partly because many tube amps are quite taxing on the power bill, so using an efficient SS amp for keeping the phone charged might save some money over time.

The phones hold the original bias for a good few minutes so that is certainly possible.

I did try something similar to that by using an SRD-7 mk2 to charge some of the phones in storage but I never pursued it further then limited testing. I was going to have a special storage cupboard built and that would include bias supplies to keep the phones always ready but it never materialized. I do think it's a good idea to let the phones rest so while I'll have a air tight cupboard built it will contain amps to warm up the phones I want to use and not bias supples.