that's all good
worth mentioning - for them (LTP) heatsink is also having role of heat-spreader, to keep them on same temp.
worth mentioning - for them (LTP) heatsink is also having role of heat-spreader, to keep them on same temp.
@RobertS61, what are you soaking your boards in? Can they be soaked with all components or should some be removed first? Greenhorn question...
Yes I know (from the manual):
"All the transistors in the product are power Mosfets, actually Hexfets from International Rectifier and Harris. These are hyper-matched parts, with gate voltages matched to 0.5% and all devices taken from the same lot codes (made on the same wafer). Most of the front end transistors, the current sources and cascode devices, are rated at 200 volts and 150 watts.
We run them at about 2.5 watts each. The speed critical actual gain devices in the front end, that is to say the actual balanced pair of transistors, are rated at 20 watts, and we run them at a watt each.
We keep them on the same heat sink so they have perfect thermal tracking.
So the paste is okay you think?
Simple Green, bottle on the left of the sink.
Cleaning Circuit Boards - Engineering Technical - PCBway
I'm finding that old goop is critical only in combination of these two factors:
-parts enduring high temperatures in operation
- change in torque of screws in time
only then there are possibilities that goop film isn't in same form and shape as on day one
if torque is good, all metal particles (of goop) are still in place and I don't care for solvent evaporated with time
you're good, just check torque (0.9Nm or nicely tight, if you don't have torque thingie) and chill
years ago - had for repair a Dynacord 4-channel monster amp, filled with Hitachi TO3 mosfet cans; all of them being on pcb, with heatsinking sandwiched in between - literally each and every one was loose ....... I was imagining them twerking by bass beats
what most surprised me - even if evidently overheated repeatedly, old buggers survived
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Haha, twerking by bassbeats, The whole amplifier will disintegrate slowly by the bass-tunes.
Thanks for your advice!
Thanks for your advice!
Thank you. No need to remove any caps, transistors, whatever? Anything else to be done after soaking or just let dry?
I desoldered all the lytics and soaked the in a solution with Simple Green and then rinsed it of with water to get rid of the lytic fluid I remember.
In the link I posted it is explained in detail.
In the link I posted it is explained in detail.
I bought those blue eyed metal Nehamiah's with a reservation.
The reservation is that if the recording has the slightest edginess around the high frequencies especially voices, it gets annoying but betters a bit when the amps are fully warmed up.
I can live with that because inserting these Pass's into my current setup is in every other dimension an improvement. Nick Drake likes them too...
I'm fully in conjunction with this IMO honest review from Doug Schroeder (2015) about the Pass XP20 & X600.5.:
"Since I had plenty of time with the Pass Labs XP-20 I was able to use it with a wider variety of speakers than usual. I had come to the conclusion a while back that the Pass Labs gear would not be a personal recommendation for audiophiles seeking to drive magnetic planar speakers without true ribbon tweeters, because I have found them as a lot to be more temperamental in the treble. I still feel that is the case, despite the obvious benefits of the X600.5’s prodigious power and current capabilities. While it would drive such a speaker easily, the strong upper end of the XP-20 and X600.5 can compound unsympathetic brightness.
The most laid back of speakers in my stable of transducers is the Daedalus Audio Ulysses, which is made more in the tradition of a high efficiency design, featuring a cabinet comprised of solid woods and carrying a slight resonance to it versus the promoted deadness synthetic materials. This speaker has twin soft dome tweeters, which is ideal for the Pass Labs XP-20 and X600.5 combo. I could do nearly anything I wanted in terms of swapping cables or the source and the Pass Labs/Daedalus pairing was never edgy. Such a speaker is romantic sounding versus surgical sounding. I suggest that Pass Labs enthusiasts lean toward designs like the Daedalus in order to avoid any risk of pushing the envelope as regards having too etched or pushed forward treble."
Source: Pass Labs XP-20 Preamplifier and X600.5 monoblock amplifiers Review - Dagogo
You can't have it all...
well, using 600 with 97.5db/W speakers is sorta overkill..... even if in comparison role, someone could understand it as recommendation
never been able to understand function of my own brain, let alone brain of Audio Reviewer
never been able to understand function of my own brain, let alone brain of Audio Reviewer
That's another thing I noticed also. Mine are around 82dB/1m/Watt but the point that I tried to make that IMO the reviewer did a honest job to describe the tonal character of the Pass combo, something you won't get when you read most of the reviews the last 25 years or so.
In the seventies and eighties TAS and Stereophile were fun to read and reviewers weren't afraid to say what they subjectively found of the gear they reviewed. Especially Harry Pierson chief editor of Pass and J. Gordon Holt in a somewhat lower tone just published their thoughts about the audio products they scrutinized. HP was sometimes very harsh about early Threshold products like the Stasis 1 or products from Mark Levinson which they (HP and John Nork) seem to dislike (the person that is) both.
Imagine that Stereophiles first Mark Levinson review was about the ML-7A in 1986 by Holt just ignoring the 14 years that MLAS/Madrigal were already pouring out products like the ML-1 and Class A mono's the ML-2's.
But they had a opinion and nowadays it seems that every product reviewed is great and the next one in line is even better...
It's no longer the reader that pays for their salaries (although they the reviewers won't make a living from it I reckon) but the advertisers.
So I liked this review and it resonated with my own findings about the Pass X600 I have.
I've another question.
The former owner installed a RCA connector on the back but did not connect it to the front-end PCB. You can see it on the back but it is hidden under the myriad of Monster Cables ls cables inside.
These first X and XA amps have been designed to only accept balanced inputs by means of a XLR connector because of their X (Su-Sy) configuration.
The later incarnations .5 and now .8 have also RCA inputs.
From the manual I know that the XLR connector is wired as follows:
pin 1 is ground, pin 2 is the positive signal and pin 3 is the negative signal.
Maybe this is a dumb question but if I want to drive my X600's with a tube pre-amp with only single-ended outputs (RCA's), how should I proceed?
Normally you would connect pin 1 ground and 3 NEG together, but would that upset the working of these amplifiers?
https://www.diyaudio.com/forums/attachment.php?attachmentid=996468&stc=1&d=1636534824
https://www.diyaudio.com/forums/attachment.php?attachmentid=996469&stc=1&d=1636534824
The former owner installed a RCA connector on the back but did not connect it to the front-end PCB. You can see it on the back but it is hidden under the myriad of Monster Cables ls cables inside.
These first X and XA amps have been designed to only accept balanced inputs by means of a XLR connector because of their X (Su-Sy) configuration.
The later incarnations .5 and now .8 have also RCA inputs.
From the manual I know that the XLR connector is wired as follows:
pin 1 is ground, pin 2 is the positive signal and pin 3 is the negative signal.
Maybe this is a dumb question but if I want to drive my X600's with a tube pre-amp with only single-ended outputs (RCA's), how should I proceed?
Normally you would connect pin 1 ground and 3 NEG together, but would that upset the working of these amplifiers?
https://www.diyaudio.com/forums/attachment.php?attachmentid=996468&stc=1&d=1636534824
https://www.diyaudio.com/forums/attachment.php?attachmentid=996469&stc=1&d=1636534824
Attachments
yup, for SE input , you need to short XLR pins 1 & 3
either use U plug short , or make it of spare male XLR cable connector
no amp upsetting, it'll work perfectly as SE/Bal converter
either use U plug short , or make it of spare male XLR cable connector
no amp upsetting, it'll work perfectly as SE/Bal converter
Hi ZenMod,
Thanks.
And the white colored input lead is ground, blue is negative and red is positive if I'm correct.
Then RCA inner pole must be connected to the red terminal and the shield must be connected to the white terminal and the I can short from the outside with a U plug (which I do have somewhere ;-)) pins 1 and 3 (blue and white).
Thanks.
And the white colored input lead is ground, blue is negative and red is positive if I'm correct.
Then RCA inner pole must be connected to the red terminal and the shield must be connected to the white terminal and the I can short from the outside with a U plug (which I do have somewhere ;-)) pins 1 and 3 (blue and white).
dunno for colors and usually I don't care, because that is not exactly standardized
what I know is
XLR pin 1 - GND
XLR pin 2 - positive hot
XLR pin 3 - negative hot
for RCA you're using GND and positiive hot, while negative hot must be grounded , as I wrote in previous post
what I know is
XLR pin 1 - GND
XLR pin 2 - positive hot
XLR pin 3 - negative hot
for RCA you're using GND and positiive hot, while negative hot must be grounded , as I wrote in previous post