Time to start this long over due thread
I just need to find one now
Maybe the posters in the DH-200/220 Mod thread can use this thread instead for these models
We are working on adapting the DH-220C design for use in DH-500 & P500 chassis
There are some new OPS boards in trial for those heatsinks.
I just need to find one now
Maybe the posters in the DH-200/220 Mod thread can use this thread instead for these models
We are working on adapting the DH-220C design for use in DH-500 & P500 chassis
There are some new OPS boards in trial for those heatsinks.
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Wow. That’s fantastic! I was checking the ebay ad and a couple questions;
- what needs to change to apply the ebay board (that only talks about dh-200/220) to a dh-500.
- in your above post you mention the ops board, but not the ips. Does that imply there is still work remaining?
Btw. I am well equipt to peform this upgrade, so only really waiting to ensure theings are stable and reliable (mostly don’t want to blow any of those hitachi outputs). I have a couple scopes, several dmms, sig generators, solder station, and don’t make as many mistakes as i used to. Most of my recent work has been on tube amps. So i think I’m ready.
P.s. i was quite pleased to find my recently acquired dh-500 in pristine unmolested condition. Pc-19c boards were running low double digit DC offsets and bias at 320 and 650 (ouch) when i got it, and i broke the locking paint on the dc offset and bias pots when i got into it. Now at 375 and dc running between +/- 2mv. I may opt to do one of my remaining dh-200’s that hasn’t been touched yet and is in greater need of a rebuild first
- what needs to change to apply the ebay board (that only talks about dh-200/220) to a dh-500.
- in your above post you mention the ops board, but not the ips. Does that imply there is still work remaining?
Btw. I am well equipt to peform this upgrade, so only really waiting to ensure theings are stable and reliable (mostly don’t want to blow any of those hitachi outputs). I have a couple scopes, several dmms, sig generators, solder station, and don’t make as many mistakes as i used to. Most of my recent work has been on tube amps. So i think I’m ready.
P.s. i was quite pleased to find my recently acquired dh-500 in pristine unmolested condition. Pc-19c boards were running low double digit DC offsets and bias at 320 and 650 (ouch) when i got it, and i broke the locking paint on the dc offset and bias pots when i got into it. Now at 375 and dc running between +/- 2mv. I may opt to do one of my remaining dh-200’s that hasn’t been touched yet and is in greater need of a rebuild first
That’s great to hear that you have a test unit up and running.
I was just recently given a pair of the later Rockford DH500 amps, both were bridged, and not working. So now I have three dead amps, and an extra transformer as well. I haven’t tested the outputs on any of the new arrivals.
I may try and configure a pair of the transformers into an isolation transformer for line conditioning.
I was just recently given a pair of the later Rockford DH500 amps, both were bridged, and not working. So now I have three dead amps, and an extra transformer as well. I haven’t tested the outputs on any of the new arrivals.
I may try and configure a pair of the transformers into an isolation transformer for line conditioning.
The Dh-220c amp front end pcb requires a few comp changes and the driver heatsinks could be beefed up using some aluminum across them
There has been one beta tester for the Dh-500c design so far, but I do not know what everyone does. I know a beta tester working on putting them in a perreaux ? chassis, so lots going on.
There has been one beta tester for the Dh-500c design so far, but I do not know what everyone does. I know a beta tester working on putting them in a perreaux ? chassis, so lots going on.
The measurement floor is the lower curve of the two graphs.
This is at a relatively low output voltage of 1.5V. The results are slightly better with higher voltage output. The load was 10 kOhm. The graph with 10 kHz maximum was filtered at 20 kHz. The Graph out to 40 kHz had an 88.2 kHz low pass filter (software based)
-Dan
This is at a relatively low output voltage of 1.5V. The results are slightly better with higher voltage output. The load was 10 kOhm. The graph with 10 kHz maximum was filtered at 20 kHz. The Graph out to 40 kHz had an 88.2 kHz low pass filter (software based)
-Dan
Hi Rick,
I have both a DH 500 and the Perreaux 3150. I’m finishing the board build on the DH 200s soon, but kept 2 boards to try on the Perreaux with 95VDC rails. Are you saying there will be a tweaked version for the higher voltage DH500. ? I have the DH500 taken apart, with some musical fidelity boards in it, but not runnung because the person i built it for decided to plug his passively powered subwookers into it at full volume one night a decade ago and Lost most of the orignial Hitachi outputs. I couldn't find outputs at time (have them now) so it sat in the corner.
(A decade later and I don’t know where the Haflers cover is) I now have both Exicon double die and Hitachi 56/176 outputs. If you want it I ‘d be glad to lend you the Hafler amp and both types of output devices as a test bed and pay for any other parts, but in the end do need to give it back to the owner when done. The Perreaux I’ve build the boards for is about 85 % done refurbished. I was concentrating on the the DH 200s first, but their almost done. .
I have both a DH 500 and the Perreaux 3150. I’m finishing the board build on the DH 200s soon, but kept 2 boards to try on the Perreaux with 95VDC rails. Are you saying there will be a tweaked version for the higher voltage DH500. ? I have the DH500 taken apart, with some musical fidelity boards in it, but not runnung because the person i built it for decided to plug his passively powered subwookers into it at full volume one night a decade ago and Lost most of the orignial Hitachi outputs. I couldn't find outputs at time (have them now) so it sat in the corner.
(A decade later and I don’t know where the Haflers cover is) I now have both Exicon double die and Hitachi 56/176 outputs. If you want it I ‘d be glad to lend you the Hafler amp and both types of output devices as a test bed and pay for any other parts, but in the end do need to give it back to the owner when done. The Perreaux I’ve build the boards for is about 85 % done refurbished. I was concentrating on the the DH 200s first, but their almost done. .
Hi Dave,
The beta tester Bill suggested a few changes to the zobel comp wattages, wind the coil with #16, beef up the driver hs as shown above, R1,2 values increased for higher V.
I can provide you the link to the docs we wrote up on the build
Bill did a great job but also drilled/tapped the HS for the new ops
Right now I am too busy but thanks for the DH-500 chassis offer to use as a test bed
Rick
The beta tester Bill suggested a few changes to the zobel comp wattages, wind the coil with #16, beef up the driver hs as shown above, R1,2 values increased for higher V.
I can provide you the link to the docs we wrote up on the build
Bill did a great job but also drilled/tapped the HS for the new ops
Right now I am too busy but thanks for the DH-500 chassis offer to use as a test bed
Rick
The Perreaux has passive heatsinks. For both the DH 500 and the Perreaux I have enough 56/176 Hitachis to match and rebuild them. I suspect the Exicons needs twice the bias current because of the dual dies at no load so there'll be thermal monitoring in addition to electrical testing. The Perreaux I used 100 watt planar resistors, 14 guage coil, and 5 parralled 630 VDC FKP Wimas to make up the 22n to get the power handling of the zobels higher
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