I wanted to mention that the X Series 600 manual on pages 15-16 has some really clear plain language and distortion curves on exactly what sysu does. The Zen articles on the Aleph current source are also very informative.
http://www.passlabs.com/pdf/old product manuals/x1k_600_350_om.pdf
This information and the previous measurements pretty well defined how best to set up the amp and listening test confirmed this.
Ah, 100 posts and over 8000 views..well someone is watching.
iMac
http://www.passlabs.com/pdf/old product manuals/x1k_600_350_om.pdf
This information and the previous measurements pretty well defined how best to set up the amp and listening test confirmed this.
Ah, 100 posts and over 8000 views..well someone is watching.
iMac
macka said:...well someone is watching.
iMac
I do
My (lack of) competence don't allows me to appear here with any kind of usefull contribution.
But I follow this great thread with highest interest and passion.
As Terry said "The data you are generating is invaluable."
Well, I 'll now return to invisibility
Manu
Glad some of you find it useful.
Unfortunately I think I may have offended some people in Graham's 100 Wattt X Aleph thread.
But unless you focus on some real specifics the whole situation becomes a mess. Otherwise you may as well buy something good and spend more time listening rather than surfing threads for hours looking for what you really need to know.
I will post details of the cascoded ZVP 2110A shortly.
Ian
Unfortunately I think I may have offended some people in Graham's 100 Wattt X Aleph thread.
But unless you focus on some real specifics the whole situation becomes a mess. Otherwise you may as well buy something good and spend more time listening rather than surfing threads for hours looking for what you really need to know.
I will post details of the cascoded ZVP 2110A shortly.
Ian
Hi Ian,
I don't think you've offended anyone over on the AX100 thread if that's the one you're referring to. At least not that I've noticed. But I've been away on holiday for a week and a half over at the Sea Ranch. And no I didn't see Nelson.
Regarding your comment on the 8000 views: I think it's totally justified because of the valuable nature of the data you're posting. The AX100 thread is over 60,000 views which amazes me. This all demonstrates that the Aleph X is still considered by many to be a mature and touchstone project.
Graeme
I don't think you've offended anyone over on the AX100 thread if that's the one you're referring to. At least not that I've noticed. But I've been away on holiday for a week and a half over at the Sea Ranch. And no I didn't see Nelson.
Regarding your comment on the 8000 views: I think it's totally justified because of the valuable nature of the data you're posting. The AX100 thread is over 60,000 views which amazes me. This all demonstrates that the Aleph X is still considered by many to be a mature and touchstone project.
Graeme
gl said:
Isn't that where you have to Rent-A-Sheep to get your lawn mowed ?
Speaking as one of the lurkers on either A-X thread, it would be great if both of you kept on fiddlin with the X + exchange numbers.
I've got some old style 600mW/40mS/30mA single and dual JFETs that i was hoping to use for a J-ed AX amp, which make both your threads interesting to monitor.(in silence)
Jacco,
Thank you for the feedback. Those JFET's sound like they would work well.
Yes there is a flock of sheep that gets moved around. But they're only placed on the common grassy fields between the houses - and held in check by a portable electric fence. The problem is that the sheepherder guy uses the roads to move the sheep. You locate the flock by following the trail of sheep ****. It's part of the charm.
Graeme
Thank you for the feedback. Those JFET's sound like they would work well.
Yes there is a flock of sheep that gets moved around. But they're only placed on the common grassy fields between the houses - and held in check by a portable electric fence. The problem is that the sheepherder guy uses the roads to move the sheep. You locate the flock by following the trail of sheep ****. It's part of the charm.
Graeme
Following the contruction of the Aleph J project and trialing those amp for a bit I revisited the Jfet input stage.
To cut a long story had a good listen to the amps tonight and I think subject to some minor adjustments they are at perfection.
To give to an example and I have this Blue Note Jazz Cd I have been using that I bought at the Blue Note Jazz Club in N.Y by Francisco Mela Melao.
Never before heard such high frequency resolution ever from a loudspeaker. Sounds like a grand statement I know but well I am comparing to every other Pass amp in the house.
The vocals have an un canny clarity and the bass rocks. The transient peformance from loud to deep silence is quite amazing even on relatively small loudspeakers like my JBL 4208 time aligned near field monitors.
This for me is a real break though using the Jfets. I can hear subtle but quite audible differences between all my digital sources.
I can only wonder what a hi end digital source would do.
An analogy is like going from 16 bit 44.1 to 24 bit 192 recordings.
So at this stage I will let it burn in a bit more for a few days and take some key measurement and hard wire the driver board wiring.
So what were the mods.
Teflon microphone OFC wiring in key areas so that the gates of the followers are wired in groups of two (not diasy chained from the driver board.)
I feed the Jfets on the daughter boards direct from the balanced input cable direct to the gates of the Jfets via a sole 10K Dale resister.
The new Silmic 11 capacitors in the current source bypassed with Panasonic PP film foil 0.022 capacitors.
Bypass the negative supply rail on the Jfet daughter board with a Panasonic 0.33 PP film foil capacitor.
Reducing the source resisters down by 30% in the output stage to 0.5R and as yet some fine adjustment to the current source current gain.
All these mods meant collectively rebuilding the amps.
I am thrilled with the outcome though and I think those that tackle this project will be quite pleased.
The feedback resisters are 220K and 22 K to ground.
I guess the key point here is careful implementation in terms of contruction and layout. Use very high quality signal wiring to minimise stray capacitance and keep all signal paths as short as possible.
If you are wondering how. Just drop Erno Borbley a line and he will kindly match some Jfets for you.
cheers
Ian
To cut a long story had a good listen to the amps tonight and I think subject to some minor adjustments they are at perfection.
To give to an example and I have this Blue Note Jazz Cd I have been using that I bought at the Blue Note Jazz Club in N.Y by Francisco Mela Melao.
Never before heard such high frequency resolution ever from a loudspeaker. Sounds like a grand statement I know but well I am comparing to every other Pass amp in the house.
The vocals have an un canny clarity and the bass rocks. The transient peformance from loud to deep silence is quite amazing even on relatively small loudspeakers like my JBL 4208 time aligned near field monitors.
This for me is a real break though using the Jfets. I can hear subtle but quite audible differences between all my digital sources.
I can only wonder what a hi end digital source would do.
An analogy is like going from 16 bit 44.1 to 24 bit 192 recordings.
So at this stage I will let it burn in a bit more for a few days and take some key measurement and hard wire the driver board wiring.
So what were the mods.
Teflon microphone OFC wiring in key areas so that the gates of the followers are wired in groups of two (not diasy chained from the driver board.)
I feed the Jfets on the daughter boards direct from the balanced input cable direct to the gates of the Jfets via a sole 10K Dale resister.
The new Silmic 11 capacitors in the current source bypassed with Panasonic PP film foil 0.022 capacitors.
Bypass the negative supply rail on the Jfet daughter board with a Panasonic 0.33 PP film foil capacitor.
Reducing the source resisters down by 30% in the output stage to 0.5R and as yet some fine adjustment to the current source current gain.
All these mods meant collectively rebuilding the amps.
I am thrilled with the outcome though and I think those that tackle this project will be quite pleased.
The feedback resisters are 220K and 22 K to ground.
I guess the key point here is careful implementation in terms of contruction and layout. Use very high quality signal wiring to minimise stray capacitance and keep all signal paths as short as possible.
If you are wondering how. Just drop Erno Borbley a line and he will kindly match some Jfets for you.
cheers
Ian
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