PassLabs X600

[RobertS61]

I also asked about DIY updates or special attention to certain parts apart from the filtercapacitors.

What I realize now that I've never seen any Threshold S or SA series, PassLabs X or XA series at (Highend) repairfacility's / specialists. Lot's of Krell, Levinson and sometimes Rowlands but never Thresholds (apart from the Stasis 3 I have) or PassLabs.
Were they sold so few? ;-)

 

[EUVL]

> So the amps are bridged?

Yes.

And the number I quoted were single ended, only as an example.
The picture remains essentially the same.
I'll let you change those to bridged configuration.


Patrick

 

[RobertS61]

Okay clear.

Thanks for your answers.

 

[Zen Mod]

examine Aleph X projects around and you'll get it - that's practically (as example) FE of Aleph 30, with additional OS mirrored from right side to left (logically driven with same FE)

since these two bridged OS are working in series, fact of one side being unable to transit to B Class applies to other side

take PL numbers as granted, do not bother with calculations

 

[RobertS61]

I'm exhausted...
Those X600's hauling alone out of my trunk is too much.
I almost went out...no kidding I almost fainted, do not try this on your own.
They look cute and relatively small compared to Krells, but they're just to massive and weigh over 50 kilograms per chassis I reckon.

 

[Zen Mod]

make permanent Dolly for each one

or just buy them

first one I found, just graphic info - I know that you're in Hollanda

Access Denied

 

[ggetzoff]

You will not need to mod these amps- you will have tons of power even with your inefficient loudspeaker: I would be shocked if you ran out of power with these beasts.

 

[RobertS61]

They even sound good just "out of the box".
Meter won't move even with Kappa 9 low end.
Low end is the best I've had, better than Krell KRS-100's.
I'm very happy with my birthday presents!

https://www.diyaudio.com/forums/attachment.php?attachmentid=994520&stc=1&d=1635872868
https://www.diyaudio.com/forums/attachment.php?attachmentid=994521&stc=1&d=1635872868
https://www.diyaudio.com/forums/attachment.php?attachmentid=994522&stc=1&d=1635872868
https://www.diyaudio.com/forums/attachment.php?attachmentid=994523&stc=1&d=1635872868
https://www.diyaudio.com/forums/attachment.php?attachmentid=994524&stc=1&d=1635872868

 

[RobertS61]

The powerlytics are happily flowing.

And little critters can live in the cellar nice and warm...

 

[ggetzoff]

The only thing that would ever need to be done to those would be a re-cap, but the factory ones are probably good for years to come.

 

[RobertS61]

Nelson said when he serviced a pair of 1980 Stasis 1's, the Mallory filtercaps were still okay. Maybe there are some low voltage smaller caps that need to be replaced? Don't know what PassLabs does with those sold in continental US.
I don't trust the distributors over here particularly with these kind of amps.

I could perform a capacitance and ESR measurement with a special meter I have for these power filtercaps...

I asked the guy I bought these from, who's trading highendaudio gear for a living at high volume low margins for 15 years, and he too couldn't remember ever seen Thresholds and/or PassLabs with his repairservices (three addresses) .
That's what I found an astonishing feat.
We both did see a lot of Levinson and Krell stuff tough for repair.

 

[RobertS61]

What I find also astonishing that these are the first big amps that are totally silent. No mechanical or electrical hum from those 15A toroidals. The fit and finish is also superb. No ringing of the cooling fins and the chassis parts fit very tight together. Must have been a tour de force 22 years ago.
Only the cooling fins are more purple than black....

 

[ggetzoff]

They are silent because the customer who would buy these new would never accept any hum or noise, and that is a fact.

 

[RobertS61]

Well that's my luck then.... But even after 20 years they're still silent.

 

[Zen Mod]

me thinks it's proper time for Official "Blame Pa!" thread

 

[RobertS61]

Yes he them made just too good so the people that bought them still have them because they refuse to break down and they do not buy new ones...

 

[JR_W]

I also have a pair of X600 amps, I call them velvet sledgehammers. Last time I had them hooked up, they were just powering a little pair of JBL 800 Arrays, but they sounded marvelous.

 

[Nelson Pass]

Nelson said when he serviced a pair of 1980 Stasis 1's, the Mallory filtercaps were still okay. Maybe there are some low voltage smaller caps that need to be replaced?

There are two power supply electrolytics on the board and a couple in the bias circuits that are low hanging fruit, but I don't think I would bother unless you hear noise or the bias gets off.

 

[RobertS61]

I also have a pair of X600 amps, I call them velvet sledgehammers. Last time I had them hooked up, they were just powering a little pair of JBL 800 Arrays, but they sounded marvelous.

Yes velvet sledgehammers, that's the exact expression for them. I managed today to get the meters moving but at discotheque levels but the control remains as the character of the sound. I'm really happy with them and disconnected all my other amps I toyed around with.

Now I have to find a good PL pre...

 

[RobertS61]

There are two power supply electrolytics on the board and a couple in the bias circuits that are low hanging fruit, but I don't think I would bother unless you hear noise or the bias gets off.

Thanks!

I hear no noise and the bias is on spec.
So I keep them hanging for a while.....

Good sounding and looking products. Thank you for making them.