Hi ZenMod,
I examined:
pin 1 is the white lead, so ground
pin 2 is the red lead, so positive signal and
pin 3 is the blue lead, so negative signal in this X600.
https://www.diyaudio.com/forums/attachment.php?attachmentid=996500&stc=1&d=1636543957
https://www.diyaudio.com/forums/attachment.php?attachmentid=996501&stc=1&d=1636543957
I examined:
pin 1 is the white lead, so ground
pin 2 is the red lead, so positive signal and
pin 3 is the blue lead, so negative signal in this X600.
https://www.diyaudio.com/forums/attachment.php?attachmentid=996500&stc=1&d=1636543957
https://www.diyaudio.com/forums/attachment.php?attachmentid=996501&stc=1&d=1636543957
Attachments
Haha, negative -> cold -> maybe bad? That blue wire caries a negative, cold and bad signal! Let's tie it to the ground! That'l teach him!
RobertS61, Next time you post pics do you think we can have a pic of the bottom of that FE board?
If I'm gonna replace the lytics on those I will post what you ask for if it is not a IP infringement although I was a IP legal expert and I know that after 10 years a patent expires also at the USPTO ...
17 I think. but it's out of production. N.P. may chime in???? Maybe even give us the schematic???
You just keep posting the top over and over? Do you realize there is a stickey from the dawn of diyAudio about this design? Thx
You just keep posting the top over and over? Do you realize there is a stickey from the dawn of diyAudio about this design? Thx
Hi ZenMod,
I saw I had a XLR - RCA cable with pins 1 & 3 shorted together in the WBT RCA connector so I used that. Before putting in operation I measured this converter signalcable with my multimeter and everything turned out fine.
Sadly when inserted between my Krell KRS-2 pre-amp and the X600's there was an immediate static hum on both speakers but the setup sounded fine.
The hum was static as said because it did not get louder when the volume increased.
I connected my Classe DR-3 which has only SE inputs and there was no hum at all...
Any ideas?
https://www.diyaudio.com/forums/attachment.php?attachmentid=997577&stc=1&d=1636886166
Attachments
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Also I would like to know what is the wavelength (nM) of the Pass LED's.
It's a kind of blue/violet in the vicinity of 430 nM I think.
But I'm not sure...although you can clearly see the violet hue on the periphery of the blue light coming of the LED.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997583&stc=1&d=1636890981
It's a kind of blue/violet in the vicinity of 430 nM I think.
But I'm not sure...although you can clearly see the violet hue on the periphery of the blue light coming of the LED.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997583&stc=1&d=1636890981
Attachments
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Better NOT. You'd make a cake mess of deep fine dust and alcohol. Take it outside and blow it out with compressed air. that's all. enjoy!
when connected with signal cable, lift one of them from safety gnd
preamp preferably
Nope...
My RCA - XLR conversion cable is technically basically the same I reasoned, as to wire the retro-fitted RCA connector on my X600's, insert a U plug between pin 1 & 3 of the XLR on the X600's and then run a standard SE cable?
My RCA - XLR conversion cable is technically basically the same I reasoned, as to wire the retro-fitted RCA connector on my X600's, insert a U plug between pin 1 & 3 of the XLR on the X600's and then run a standard SE cable?
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The only thing that works is to lift ground on both X600's.
I grounded the pre-amp again so now there's a one-point grounding through the pre-amp, but I'm hesitating but in the combined manual of the X1000/600/350 it is stated:
"The chassis of the X1000 is connected to the earth ground through the power cord. This is the
only thing it connects to. It is not attached to the circuit or to the amplifier signal ground. This
is essential to operating the amplifiers in series or parallel configurations.
The X600 and X350 have their circuit grounds attached to the chassis in the conventional manner.
Under no circumstances should you defeat the ground connection of the power cord. For your
safety, the chassis of the amplifier should be earth grounded. We aren’t kidding."
We aren't kidding does sound pretty serious.
I grounded the pre-amp again so now there's a one-point grounding through the pre-amp, but I'm hesitating but in the combined manual of the X1000/600/350 it is stated:
"The chassis of the X1000 is connected to the earth ground through the power cord. This is the
only thing it connects to. It is not attached to the circuit or to the amplifier signal ground. This
is essential to operating the amplifiers in series or parallel configurations.
The X600 and X350 have their circuit grounds attached to the chassis in the conventional manner.
Under no circumstances should you defeat the ground connection of the power cord. For your
safety, the chassis of the amplifier should be earth grounded. We aren’t kidding."
We aren't kidding does sound pretty serious.
hey boyz look the solder in da pic !! clean the solder
But not with alcohol. LOL I tried that with my comeback built M2x and it made a complete mess. Maybe my solder is old school, I don't know.
I think when this amp was made they were still selling good solder, and good solder remover that was also ozone remover. 😉😱
As said in Post 88 of this thread I bought a Krell KRS-2 to supply signal to the X600's.
I have fond memories of this pre-amp from more than a decade ago and this one was in mint state and well taken care of.
To my surprise it was already serviced (caprevision) and it was done very good.
Luckily the Spectrol 100 series wirewound pot was still in which was used by Levinson also in their more expensive ML series pre-amps like the ML-1 and ML-7.
Most were substituded by the Penny + Giles RF15 plastic conductive rotary fader which was less troublesome, but experts in the field say the Spectrol was the better sounding one.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997840&stc=1&d=1636971977
The KRS-2 and X600 combine very fine together. The sound is sweet and powerful and the texture in especially the lower register is phenomenal which I already expected with this combination.
Technically it is a different story.
The KRS-2 has only a SE output.
I have to lift the ground from both X600 amplifiers to get rid of the hum.
If I only lift the ground from the KRS-2 it helps only a little.
As stated yesterday with all units properly grounded there is hum but when listening they still sound great together.
I do not feel entirely comfortable lifting the ground from the X600's but I've done sillier things with a pair of Krell KMA-200's in the far past when I was a college student and the automatic breakers in my apartment kept cutting the AC when I tried to startup these monsters so I rewired my AC around those AC breakers all together and now there only was a 20A (220VAC) in series.
That's pretty stupid of course but fear was not in my head when I was young....
I can also use the already installed RCA receptacle in the back of the X600, wire that into the main PCB (pin1 ground and pin2 positive) and use a RCA - RCA cable and a U plug into the XLR connector of the X600 to short pin1 and 3 negative signal.
Love to hear from you!
Robert
I have fond memories of this pre-amp from more than a decade ago and this one was in mint state and well taken care of.
To my surprise it was already serviced (caprevision) and it was done very good.
Luckily the Spectrol 100 series wirewound pot was still in which was used by Levinson also in their more expensive ML series pre-amps like the ML-1 and ML-7.
Most were substituded by the Penny + Giles RF15 plastic conductive rotary fader which was less troublesome, but experts in the field say the Spectrol was the better sounding one.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997840&stc=1&d=1636971977
The KRS-2 and X600 combine very fine together. The sound is sweet and powerful and the texture in especially the lower register is phenomenal which I already expected with this combination.
Technically it is a different story.
The KRS-2 has only a SE output.
I have to lift the ground from both X600 amplifiers to get rid of the hum.
If I only lift the ground from the KRS-2 it helps only a little.
As stated yesterday with all units properly grounded there is hum but when listening they still sound great together.
I do not feel entirely comfortable lifting the ground from the X600's but I've done sillier things with a pair of Krell KMA-200's in the far past when I was a college student and the automatic breakers in my apartment kept cutting the AC when I tried to startup these monsters so I rewired my AC around those AC breakers all together and now there only was a 20A (220VAC) in series.
That's pretty stupid of course but fear was not in my head when I was young....
I can also use the already installed RCA receptacle in the back of the X600, wire that into the main PCB (pin1 ground and pin2 positive) and use a RCA - RCA cable and a U plug into the XLR connector of the X600 to short pin1 and 3 negative signal.
Love to hear from you!
Robert
Attachments
using that RCA on back of amps is going to be same electrically as you did with RCA-XLR cable
if you have FID switch in your electrical installation, you're good whatever you do - feel free to lift safety gnd from XA, as long they are connected to preamp which is connected to sagety GND
under one condition - confirm with DMM that you have continuity between audio GND and cases of X600
but- absolutely best thing to try is to replace direct connection between audio GND and case with diode bridge-cap-NTC combo
shown in F5T article, page 11 (ok, without cap, but adding it across NTC is trivial - 100n up) https://www.firstwatt.com/pdf/art_f5_turbo.pdf
shown also in various threads here ........ but dunno which ones exactly
edit: see this one too http://hifisonix.com/wordpress/wp-content/uploads/2019/02/Ground-Loops.pdf
generally - problem you have is originating from preamp - I can bet it have common GND for both channels, also hard tied to safety GND/chassis; in case that you have proper dual mono preamp, or at least audio GND properly elevated from chassis, you wouldn't have these problems
if you have FID switch in your electrical installation, you're good whatever you do - feel free to lift safety gnd from XA, as long they are connected to preamp which is connected to sagety GND
under one condition - confirm with DMM that you have continuity between audio GND and cases of X600
but- absolutely best thing to try is to replace direct connection between audio GND and case with diode bridge-cap-NTC combo
shown in F5T article, page 11 (ok, without cap, but adding it across NTC is trivial - 100n up) https://www.firstwatt.com/pdf/art_f5_turbo.pdf
shown also in various threads here ........ but dunno which ones exactly
edit: see this one too http://hifisonix.com/wordpress/wp-content/uploads/2019/02/Ground-Loops.pdf
generally - problem you have is originating from preamp - I can bet it have common GND for both channels, also hard tied to safety GND/chassis; in case that you have proper dual mono preamp, or at least audio GND properly elevated from chassis, you wouldn't have these problems
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Thanks ZenMod!
With a multimeter lead connected to AC ground (black crocodile clip on the ground of the AC receptacle) and the red pin connected to a steel part screws or as shown in picture, I got for both X600's a zero reading when in Ohm mode on the MM.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997872&stc=1&d=1636978998
https://www.diyaudio.com/forums/attachment.php?attachmentid=997873&stc=1&d=1636978998
https://www.diyaudio.com/forums/attachment.php?attachmentid=997874&stc=1&d=1636978998
So that's a relieve....
In my AC configuration I have a FID device which tripped always when my CJ EVO 2000 hybrid closed it switch to connect the PSU with the outputsection after the predriver tubesection warmed up...
I have a couple of new bridges lying around, as depicted in your very informative PDF link Ground-Loops.pdf from Hifisonix, so I will explore that solution as also shown in the F5 Power Amplifier PDF on page 11 where you can see the bridge in the schematic:
https://www.diyaudio.com/forums/attachment.php?attachmentid=997876&stc=1&d=1636979704
Then I connect the bridge in between the earth of the PSU and the chassis earth point. I have to follow this thick black wire I think:
https://www.diyaudio.com/forums/attachment.php?attachmentid=997877&stc=1&d=1636980599
that probably runs downwards to that common ground.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997879&stc=1&d=1636980780
I hope I did not miss anything.
With a multimeter lead connected to AC ground (black crocodile clip on the ground of the AC receptacle) and the red pin connected to a steel part screws or as shown in picture, I got for both X600's a zero reading when in Ohm mode on the MM.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997872&stc=1&d=1636978998
https://www.diyaudio.com/forums/attachment.php?attachmentid=997873&stc=1&d=1636978998
https://www.diyaudio.com/forums/attachment.php?attachmentid=997874&stc=1&d=1636978998
So that's a relieve....
In my AC configuration I have a FID device which tripped always when my CJ EVO 2000 hybrid closed it switch to connect the PSU with the outputsection after the predriver tubesection warmed up...
I have a couple of new bridges lying around, as depicted in your very informative PDF link Ground-Loops.pdf from Hifisonix, so I will explore that solution as also shown in the F5 Power Amplifier PDF on page 11 where you can see the bridge in the schematic:
https://www.diyaudio.com/forums/attachment.php?attachmentid=997876&stc=1&d=1636979704
Then I connect the bridge in between the earth of the PSU and the chassis earth point. I have to follow this thick black wire I think:
https://www.diyaudio.com/forums/attachment.php?attachmentid=997877&stc=1&d=1636980599
that probably runs downwards to that common ground.
https://www.diyaudio.com/forums/attachment.php?attachmentid=997879&stc=1&d=1636980780
I hope I did not miss anything.
Attachments
that chassis is connected to IEC mid pin, we know that
what you need is to check connection between audio GND and chassis
practically XLR pin 1 and chassis
funny how you decided to mess with AC receptacle, instead of measuring at IEC on back of amp, or mains cable connected in/to amp
avoid dealing with AC receptacle, when you don't need to
what you need is to check connection between audio GND and chassis
practically XLR pin 1 and chassis
funny how you decided to mess with AC receptacle, instead of measuring at IEC on back of amp, or mains cable connected in/to amp
avoid dealing with AC receptacle, when you don't need to
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