spritzer

That's enough about those inferior dynamics!!! So I've been working on this SR-Omega that needed some TLC. I don't think I've ever posted pics of an empty SR-Omega shell to show why I sometimes call them the tin cans... As you can see the cups are very thin and it is mostly just plastic in there. Couple that to the huge driver and no wonder they get a bit ill tempered at higher volume levels. Far cry from the SR-007 design where the drivers are securely mounted in a large slab of metal. Another insteresting bit is that Stax grounded the metal enclosure through large resistors to the + and - terminals.

You only need to alter the gap between the diaphragm and the magnets a little bit to loose a lot of sensitivity so there could be tweaks done to the drivers you could never spot unless you opened them up. I don't get the benefits of marketing a headphone like this though where a B22 or a Dynahi/Fet are your only realistic options for driving it.

More voltage swing and higher slew rate and the biggest factors.

I can always supply red vodka if it helps my US legal team. Get better soon Al. Yesterday I had a mini-meet here with Stuart which was basically us talking until midnight with about 10 minutes of listening thrown in. Pretty much the definition of a mini-meet... Today I was busy with cleaning up the house and even attempted to sort out all the DIY related parts cluttering up the place. That pretty much failed...

It would limit the voltage to 400V but I've been using them in the BH PSU's for years now with good results.

In terms of high end audio a 3.2:1 markup would be very much on the low side.

Most XLR adapters ground the - signal but that could be causing issues here.

Welcome to the wonderful world of transistors, here one day and gone tomorrow...

If the IC's are shorting out then it could present like that. Have you tried another set?

Here I was thinking Marc had finally lost it, worrying about how fuses sound etc...

You guys could also switch to 230V...

The chassis mounted sinks are simply out of the question and that's that. This is an amp meant to bring close to TOTL performance at a budget price and designed so that anybody can build it.

It's a fully balanced amp but you only have to ground the - input if using it single ended.

As it stands now, we will offer one PSU only for the foreseeable future. There is also no need to keep posting your interest in this project, we only need that once the preorder thread goes up. There will be enough boards for everyone.

I do have a question for the group, would you want a cheap PSU that is good and does the job well or balls to the wall T2 type PSU? The difference in cost will be substantial so it is something Kevin and I are discussing. The CMF70 would work but isn't that way too big? The output resistors (the reason why they aren't normal metal films in the T2, ditto for the Stax amps) but stuff like the feedback line is split up. The boards will be open to everyone and nothing has been decided wrt a group buy of parts. Given the huge logistical nightmare of getting things to me it might not even happen.

There isn't much to the BOM to be honest. All the resistors will be the 1/2W Xicon units we used for the T2 (the Vishay RN60's are only rated for 300V) but you can also use the 1/2W PRP's and other resistors designed for use in tube amps (i.e. with high voltage handling). The values for everything are on the board as well. There are still some things that have to be ironed out like for instance who will handle the distribution of the boards (probably me) and are we going to include any parts with the boards. Not everything can be bought from Mouser so are we going to include those parts in some kind of a kit.

I could deal with Canada but not the US... As for a BOM, it will come in due time.

Wow, the gain of that amp is really on the low side. Even the tiny Stax amps have enough gain for earsplitting levels.

Better amplification does indeed help with this on the SR-007 but they will never be "flashy" about their detail retrieval. It's there but never in your face like some supposedly detailed transducers. The soundstage can also become wast with a good amp but only if that's what the recording calls for.

"One of us, one of us, one of us...." Congrats and and damn straight in comparison to the HD800.

Isn't this the trend with all Audio-GD products. Noobs think they are the bees knees but seasoned ears expose them for the subpar crap they really are?

I looked into driving from Boston to Chicago for CanJam but quickly abandoned it. 8 hours in Iceland lands you on the other side of the island...

Yup, I think Edwood did that. I want to do something similar with amps but not rely on double blind. I want to expose the "mmmm pretty" bias...

The resistor is indeed there just to protect the user. As for the cap, most of the older amps have it. I've been working on a SRM-Xs today (introduced in 1990) and it has it, same as the SRM-1 Mk2 PP (circa 1990 as well). I do think it is there just to provide some extra filtering as for instance in the SRM-Xs the bias supply is taken directly off the B+ rail. With the minimal filtering found in the amp it should help.

There is one more problem with DIY, it often costs less which is why it must sound worse. I've always wanted to test just how much perceived value is an effect with this stuff...