spritzer

That's my take on it as well but on top of that I'm just an anal bastard. The differences between the Mk1 and Mk2 SR-007 may be minor in absolute terms (both are brilliant transducers) but to my ears one is the best headphone ever made and the other is far from it.

The BH just gets out of the way and lets the phones do their thing. Not only from a fully DC-coupled neutrality standpoint but by supplying the phones with all the current they need, no matter the load. At first glance this appears to be a boost to the bass region and some extra treble but change the fit to make the bass a bit leaner and it all snaps into place. The BH will never be an amp to impress and it gives ruthlessly revealing a whole new meaning. The ES-1 is a very limited from a design standpoint and no amount of bling caps and other crap like that will fix it. It is after all just a 1968 Stax design, a good one though but it lacks all the refinements that the last 40 years have brought us. Then you add the crap construction and the possible filament fiasco and amp will chew through those expensive tubes in no time. Before you commit to anything but new production tubes in the ES-1 I would have it checked out to see if the same filament wiring is feeding the entire amp. I've heard enough horror stories... That said you might prefer the ES-1, hell you liked the Jade after all and the ability tube roll may be appealing to some. With the old BH I tried every EL34 I could get my hands on but after that the Mullard XF2's were the only ones I used and a single quad at that.

The ESP10 bias is somewhere around 500v but I'm not sure exactly what. The latest Jecklins were 1500v or something like that with an even more voltage on the stators then Stax. Shame about the crap housing though...

The 6CA7's offer more bass (the bloated and messy type though) but the midrange is a mess. They work ok with the HE90 and are rumored to be better in the ES-1 since they can handle the abuse which the grounded heater dishes out.

The T-50v1 was awesome with that amp...

Stacked stators are definitely on the to-do list. Perhaps Naaman could chime in what the bias for the output stage is. Considering he's using similar heatsinks as Justin used in the older amps he must have scaled back the bias. The difference on my old unit was night and day. Even brilliant new production tubes like the SED lacked a whole lot compared to the Mulllards.

That could be done... When I'm "done" with this amp phase I'll build some transducers just for kicks. How about wire stators for an ESP?

That's why I always wanted to see a picture of the Purtscheller phones, to see how he would make a Float in a wooden housing... It would also be cool to transform a set of floats into some desktop speakers.

They really do need a better frame...

Happy birthday Colin!!

You could very well be right if there are indeed only 6 wires on the transformer.

The transformer could have 100v taps as well so the whole thing would be series connected. Best way to check is with an ohm meter but it requires you to open up many insulation that there is on the connected wires. Not a big deal really...

Ok, no markings then. What you can do is to look at the wires which come from the AC input and into the transformer. If the voltage is switchable then you have 4 wires grouped together (could be more) which are then tied to the AC input in some way. For 230v the two center wires are connected together and the other two tied to the AC.

Happy birthday!!!

The Mk1 has never lacked any treble to my ears and is a welcome break from all those transducers out to impress with an exaggerated treble. The is almost identical but the slightly more forward nature makes it better for more upbeat music as the bass has a just a bit more attack after they have been modified. With the followers then the amp could have a chance of driving the 007's but it simply remains to be seen.

O2 killer!!!! ...

It's leather!!!!! The Mk2 is slightly more forward then the Mk1 so the treble is a bit more expressive but it's by no means a big difference.

You are using output caps which will limit the bandwidth of the amp.

I do believe that the transformer is a custom unit as what other design has use for the impedances involved. Do you see many speaker amps with 300ohm output taps, let alone 30 or even 20ohm? The fact that a transformer can be bought now proves nothing as it had to be available before the 307a was designed to be relevant.

With the F5 under way we need to shift the Aleph so pictures when you can.

I use Audiogon quite often and get offers from all around the world. Most components are easy to change to 117 which would open up the buyers pool. Do you have any internal pics of the Aleph or the make/model of the transformer?

Did you ever try to sell the Aleph on Audiogon? There appears to be some market for the DIY Pass stuff. It's much cheaper the ebay too.

SAVING UP!!!!!! You Scot's and your crazy ideas...

It's been confirmed that the pic is free to be posted so here you go:

Ok, but wasn't it behind closed doors? Hey, I'm a Nordic God so I can do what I please. If that's dressing up in drag then thats my business...