[Varejao17]

Nobody here but us chickens...

ed

 

[Roy G. Biv]

Nobody here but us chickens...

ed

 

[tincanear]

25 years old VanMedevoort monoamps. PA333 (300watts and 220 RMS; damping factor 1500) Ad, designer and builder calls it a dynamic class A design (i think similar to Continuity).
I checked with the company and they use these nowadays (they still do upgrades) So i changed two old Philips 22000 uF to four EPCOS 10000 uF.

How much caps do you recommend? And how does that work? Could you eleborate on the CRC, no clue what that is. Thanks

@Derrick Swart I was joking about adding more capacitors (that's why the smiley face emoticon)

However, since you have four 10000uF EPCOS per amplifier already, the fitment of CRC may not be that difficult with the advice and recommendation of VanMedevoort.

presumably, for each power supply rail, you have two 10000 uF capacitors connected in parallel. In the case of CRC, the grounded leads of the 4 capacitors would still be connected directly together, first capacitor fed from the rectifier bridge, and a low ohmic value power resistor, say 0.33 ohms / 10W would connect the two capacitors on the positive rail together, and power to the amp board taken from the second capacitor, and similarly another power resistor for the negative rail. Design aim is to decrease the power supply ripple voltage for lower hum (but increases the power supply impedance a bit, there is no free lunch).

for schematic examples, designer Nelson Pass (formerly of Threshold, First Watt, etc.) has used CRC configs on this products, including his DIY enthusiasts site PassDIY.

 

[Les Strat]

My worry days about Aegir going into protection because of low impedance swings is over.

This is the impedance and phase swing with the resulting EPDR (Equivalent Peak Dissipation Resistance) of my Quad ESL-63 Plus speakers as of this week.
Dotted: phase angle (max +21, min -12) , Green: impedance (max 15 ohm, min. 7 ohm), Blue: EPDR (not below 6 ohm).
These are great numbers for a full range electrostat.
Most of these type speakers go down to something like 1 ohm at 20 kHz with an impossible phase angle, what makes them a difficult to impossible load for a lot of amps.
I used to drive the Aegir's into protection when playing a bit too loud, but not anymore. Happy as a clam.



This is the Stereophile impedance measurement for the same speaker in their review from 1989.

@wout31. I feel that I have missed out as I have never heard a pair of Quad ESLs!
From what I have read and reports from people who have owned them, they are like no other speaker, especially in the midrange.
I daren't audition a pair at this late stage, as I might like them too much
In an industry which is so full of hype and BS from manufacturers ( Schiit excluded..) Quad's ESLs really do qualify as genuine design classics.
I also remember Quad's 405 'Current Dumping' amplifier receiving the 'Queen's Award for Technological Achievement' way back in 1978!
Wasn't it Peter Walker who also came up with the line 'the perfect amplifier is a straight wire with gain'.?

 

[joe]

Mod note: Guys, we've removed a few posts regarding politics per the Rules and Terms of Use.

 

[valiant66]

@wout31. I feel that I have missed out as I have never heard a pair of Quad ESLs!
From what I have read and reports from people who have owned them, they are like no other speaker, especially in the midrange.
I daren't audition a pair at this late stage, as I might like them too much
In an industry which is so full of hype and BS from manufacturers ( Schiit excluded..) Quad's ESLs really do qualify as genuine design classics.
I also remember Quad's 405 'Current Dumping' amplifier receiving the 'Queen's Award for Technological Achievement' way back in 1978!
Wasn't it Peter Walker who also came up with the line 'the perfect amplifier is a straight wire with gain'.?

I own a Quad 405, factory upgraded to a Mk II back in the 80's. It was the first HiFi piece of gear I saved up for rather than impulse purchased, followed by LS3/5a's.

The owners manual includes instructions on how to access the interior to move a jumper so you can reduce the power output from a then-outrageous 100W to 35W, to make it safe to use with the ESLs.
.

 

[RickB]

AKM is planning to outsource production of chips affected by factory fire, according to unconfirmed reports.

https://audioxpress.com/news/akm-semiconductor-audio-dac-and-adc-production-disrupted-by-fire

 

[Pietro Cozzi Tinin]

Mod note: Guys, we've removed a few posts regarding politics per the Rules and Terms of Use.

Wow. You have a lot of badges in your header.
Reminds me of the scouting.

 

[wout31]

@Les Strat, @valiant66 Peter Walker was a true audio enthusiast and a genius mind. Started out with public announcement tube amps for the London underground and moved to "domestic" audio (the D in Quad).
The II (tube) 303 amp, 405 current dumping amp all are unique and seasoned designs that make me smile as I see the resemblance with designs that @Jason Stoddard is coming up with. Not following the easy path hundred or even thousands of amp designers took (standard Linn topology) but look for a different route.

Yes Peter walker was the one who phrased "wire with a gain", knowing that no one ever could make that work. But I can tell you a set set of mono Aegir's comes close, very close.
The electrostatic full range loudspeaker, simply called ESL, was a industry standard shifting product in 1957 when it was first released. Stayed there for may years and still is a sound and style icon appreciated by many.
It's successor was even more unique with an imaginary point source 30 cm behind the speaker (man how that works for imaging and sound stage) and yes, an ESL can not be matched by anything in midrange (vocals) and detail. No honest competition if you only have to move 5 grams over two speakers, the total mass of the moving diaphragm and a true piston working.
It took Peter Walker 17 years!! to get it working. Design started in 1963, hence the model name, but it was only released in 1981.
So you Schiit heads be patient with those Schiit guys and girls on the transport and the gadget, something unique takes time, lots of it.
Only time will tell if all, some, most of the Schiit products will be sought after products decades after the demise of the company.
I mean, buying a speaker that was designed in 1955, marketed in 1957 and is still sought after in 2020, how weird can it be.

Luckily the days of having to reduce the wattage to 35 watt to keep the ESL's from breaking down are in the past. Sadly the China build product are crap.

PS. If anyone in the UK can bring me in contact with a person that knows something about the next project Peter Walker started after the ESL-63 but never finished, "The Balls", that would be a dream come true. I have read that some (only a few) survived when Quad was sold to IAG. I would love to have a peak inside to get a glimps of what he had thought up for his next step.

PPS Yes I'm a huge fan. Sorry for that. But I'm also a huge Schiit fan. Hope that is a bit of compensation.

 

[andrewmg]

Anyone had luck getting ahold of Schiit service lately? I sent a service inquiry regarding my Mjolnir 2—accidentally dropped a screw into it and something blew—a week and a half ago through the website, and there's been no response so far, despite two follow-up emails to info@schiit.com. If things are just slow at the moment, that's fine, but it seems like others in this thread have (at least as of a couple months ago) been getting much faster responses. So any recent reports would be quite welcome.

Also, as a bit of advice to owners of Schiit's tube-based amps: don't drop a screw into them! Fortunately, I was able to appropriate an Asgard 3 from my Corona-vacated office.

 

[tincanear]

Anyone had luck getting ahold of Schiit service lately? I sent a service inquiry regarding my Mjolnir 2—accidentally dropped a screw into it and something blew—a week and a half ago through the website, and there's been no response so far, despite two follow-up emails to info@schiit.com. If things are just slow at the moment, that's fine, but it seems like others in this thread have (at least as of a couple months ago) been getting much faster responses. So any recent reports would be quite welcome.

Also, as a bit of advice to owners of Schiit's tube-based amps: don't drop a screw into them! Fortunately, I was able to appropriate an Asgard 3 from my Corona-vacated office.

perhaps their computers are undergoing some Windows 10 upgraditis. I had one machine unexpectedly "upgrade" to W10 version 2004, which rendered it useless for several hours. or it might be increased volumes from holiday orders. either way, you could send a PM to Jason.

I am curious to know your impressions between the MJ2 and A3. also, what headphones are you using?

 

[wout31]

Anyone had luck getting ahold of Schiit service lately? I sent a service inquiry regarding my Mjolnir 2—accidentally dropped a screw into it and something blew—a week and a half ago through the website, and there's been no response so far, despite two follow-up emails to info@schiit.com. If things are just slow at the moment, that's fine, but it seems like others in this thread have (at least as of a couple months ago) been getting much faster responses. So any recent reports would be quite welcome.

Also, as a bit of advice to owners of Schiit's tube-based amps: don't drop a screw into them! Fortunately, I was able to appropriate an Asgard 3 from my Corona-vacated office.

Sales responded promptly last week.
Have you looked in your spam box? Sometimes happens with automated mail.

 

[andrewmg]

I am curious to know your impressions between the MJ2 and A3. also, what headphones are you using?

Focal Clears. Both amps are slightly warm of neutral, the Asgard 3 more so. The Mjolnir 2 is much more resolving and pairs remarkably well with the Clears--an end-game setup for me, assuming Schiit can repair the amp!

Sales responded promptly last week.
Have you looked in your spam box? Sometimes happens with automated mail.

Yes, that was the first place I looked, but nothing there.

 

[tincanear]

@andrewmg worst case, the MJ2 will need a new PCB assembly. but, hopefully Jason or a senior tech there could fix it. burn marks could give them a hint where to start replacing parts.

would the repair / replacement be covered by a credit card accidental damage warranty?

 

[Les Strat]

@Les Strat, @valiant66 Peter Walker was a true audio enthusiast and a genius mind. Started out with public announcement tube amps for the London underground and moved to "domestic" audio (the D in Quad).
The II (tube) 303 amp, 405 current dumping amp all are unique and seasoned designs that make me smile as I see the resemblance with designs that @Jason Stoddard is coming up with. Not following the easy path hundred or even thousands of amp designers took (standard Linn topology) but look for a different route.

Yes Peter walker was the one who phrased "wire with a gain", knowing that no one ever could make that work. But I can tell you a set set of mono Aegir's comes close, very close.
The electrostatic full range loudspeaker, simply called ESL, was a industry standard shifting product in 1957 when it was first released. Stayed there for may years and still is a sound and style icon appreciated by many.
It's successor was even more unique with an imaginary point source 30 cm behind the speaker (man how that works for imaging and sound stage) and yes, an ESL can not be matched by anything in midrange (vocals) and detail. No honest competition if you only have to move 5 grams over two speakers, the total mass of the moving diaphragm and a true piston working.
It took Peter Walker 17 years!! to get it working. Design started in 1963, hence the model name, but it was only released in 1981.
So you Schiit heads be patient with those Schiit guys and girls on the transport and the gadget, something unique takes time, lots of it.
Only time will tell if all, some, most of the Schiit products will be sought after products decades after the demise of the company.
I mean, buying a speaker that was designed in 1955, marketed in 1957 and is still sought after in 2020, how weird can it be.

Luckily the days of having to reduce the wattage to 35 watt to keep the ESL's from breaking down are in the past. Sadly the China build product are crap.

PS. If anyone in the UK can bring me in contact with a person that knows something about the next project Peter Walker started after the ESL-63 but never finished, "The Balls", that would be a dream come true. I have read that some (only a few) survived when Quad was sold to IAG. I would love to have a peak inside to get a glimps of what he had thought up for his next step.

PPS Yes I'm a huge fan. Sorry for that. But I'm also a huge Schiit fan. Hope that is a bit of compensation.

Thanks very much for this @wout31
Fascinating stuff!
I'll see if I can find out anything about Peter Walker's project after the ESL 63