Another d-500 rep
- Thread starter grapplesaw
- Start date
The AP gave me some worry today
I replaced the right channel Ic to a Matched lf351 and put in new 7,5K 5watt Power resistors along with two new each 2n3439 and 2n5416's fired up left channel at 160 volts across the caps 115 line voltage and 8.5 mv DC offset +14.6 v and -14.7 v on the board.
Ran up to 2.7 volts out (1 watt) then increased voltage to full 230
across the caps. All was uneventful. (It still has one empty hole on the positive left channel to fill)
Now the AP troubles.
I then increased the output to 4 volts but noticed no N+THD reading just 00000. I dropped back and the reading returned but as I increased output the relays to auto tune power levels clicked but got 00000. Switched channels with same result. Ugh!!! Need a service manual, if you have one Lee. I am sure it is a relay not contacting properly. After waking away for an hour I quickly tested it and all is well again. But for how long ???
I replaced the right channel Ic to a Matched lf351 and put in new 7,5K 5watt Power resistors along with two new each 2n3439 and 2n5416's fired up left channel at 160 volts across the caps 115 line voltage and 8.5 mv DC offset +14.6 v and -14.7 v on the board.
Ran up to 2.7 volts out (1 watt) then increased voltage to full 230
across the caps. All was uneventful. (It still has one empty hole on the positive left channel to fill)
Now the AP troubles.
I then increased the output to 4 volts but noticed no N+THD reading just 00000. I dropped back and the reading returned but as I increased output the relays to auto tune power levels clicked but got 00000. Switched channels with same result. Ugh!!! Need a service manual, if you have one Lee. I am sure it is a relay not contacting properly. After waking away for an hour I quickly tested it and all is well again. But for how long ???
- Joined
- Jan 14, 2011
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- Halfbiass...Electron Herder and Backass Woof
I guess I need new drivers
So I blew two drivers in the right channel today while testing.
I had it a back together and was testing the unit at 1 watt output and run up in the high frequecy range between 10k and 40k. At about 13 k it titled.
Why did I do this? Who knows.
Its all all because of Lee. With his influence I bought some Khorns. I have then set up in my listening room with a 700WOPL diving them. They sound great.
I had finished the dual500 from Ed and wanted to test it out for reliability So each day I fire it up through my Genesis 310, of which I like very much. After a short while I seem to turn over to the Khorns as they are much better sounding. This made me curious.
I was thinking about why they were so much different and thought of the multiple ferric beads on the base of the drivers of the Dual500 and What they may be doing to the high frequecy annulling. First I put an 700WOPL on the Genesis and sure enough there is much more high end. This is is what I was used to.
So so in order to look into it a bit deeper I fired up the second D500 I just finished. I had not replaced drivers , just those that had failed. So lesson learned is replace all outputs on rebuild.
Next step. While testing at higher frequency I did notice the output was less in the 20-40krange and was jut about to note the voltage at each 1,000k when it took out the two drivers.
I would like to retest this without any new drivers installed and will do
so question is there a max frequency to run up to and at what power setting?
Second question is are ferric beads needed when going to full complimentary setup. Joe's backplate have no such dampening in their.
Did the quasi comp setup have high frequency osculations in only the series two set up?
the Phase linear guys must have struggled with the lf356 ic and Mj1524 outputs(tp9024)
so so I guess I do not know what the best way to test the ferric bead diffences of how many and there placement has on the final output.
Phase linear put different amounts of ferric beads on the positive vs negative base feed and at different locations along that path. The series two 700 has one only on the positive bank.
I added one two each side on the full complimentary c-500 build. Any input if they are even needed and any of the above would be welcome
So I blew two drivers in the right channel today while testing.
I had it a back together and was testing the unit at 1 watt output and run up in the high frequecy range between 10k and 40k. At about 13 k it titled.
Why did I do this? Who knows.
Its all all because of Lee. With his influence I bought some Khorns. I have then set up in my listening room with a 700WOPL diving them. They sound great.
I had finished the dual500 from Ed and wanted to test it out for reliability So each day I fire it up through my Genesis 310, of which I like very much. After a short while I seem to turn over to the Khorns as they are much better sounding. This made me curious.
I was thinking about why they were so much different and thought of the multiple ferric beads on the base of the drivers of the Dual500 and What they may be doing to the high frequecy annulling. First I put an 700WOPL on the Genesis and sure enough there is much more high end. This is is what I was used to.
So so in order to look into it a bit deeper I fired up the second D500 I just finished. I had not replaced drivers , just those that had failed. So lesson learned is replace all outputs on rebuild.
Next step. While testing at higher frequency I did notice the output was less in the 20-40krange and was jut about to note the voltage at each 1,000k when it took out the two drivers.
I would like to retest this without any new drivers installed and will do
so question is there a max frequency to run up to and at what power setting?
Second question is are ferric beads needed when going to full complimentary setup. Joe's backplate have no such dampening in their.
Did the quasi comp setup have high frequency osculations in only the series two set up?
the Phase linear guys must have struggled with the lf356 ic and Mj1524 outputs(tp9024)
so so I guess I do not know what the best way to test the ferric bead diffences of how many and there placement has on the final output.
Phase linear put different amounts of ferric beads on the positive vs negative base feed and at different locations along that path. The series two 700 has one only on the positive bank.
I added one two each side on the full complimentary c-500 build. Any input if they are even needed and any of the above would be welcome
Last edited:
- Joined
- Jan 14, 2011
- Messages
- 74,944
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof