Hafler dh 500 audiokarma. I have a Hafler DH-110 and a DH-220 as backup spares.
Hafler dh 500 audiokarma. Aug 18, 2024 · Hello everyone, I have a DH-500 that recently had the right channel stop putting out sound. I know for a fact that one or all of the mosfet transistors are bad on the left channel. Since the early boards have only one trim pot, (bias) I checked Jun 23, 2011 · AudioKarma Audio Forums. Nov 13, 2017 · I bought a Hafler DH-500 amplifier last spring, it had been recapped and a new power switch and fan were installed. Unless one or both of these amps has been modded, the Hafler is of a later and better generation, more able to handle tricky loads. The amp turns on just fine, the relay clicks, and the left channel works perfectly but the right only gives a faint noise. It also presented as excessive current draw at the rail fuses. I was very happy with both. Could be a fun project. Here is a link to the full dh-500 manual I just put up on my ftp server (in pdf format). Verify that the original channel still works, and then start to check the parts on the failing driver board. Hafler DH 500. Feb 3, 2020 · As for the DH-500, that is still in the works for qualification at the +/-90V supply V. See if you can find out how that amp was assembled. Let's keep problems 'read on the internet' in context, here. Apr 12, 2011 · The DH-500 is a stereo amp that weighs 50 pounds and is said to be conservatively rated at 225w per channel @ 8ohms. Solid State Hafler DH 500 Faceplate Needed. I've never seen the DH-500, but it's a real hoss. Aug 10, 2018 · Up to recently I had no interest in vintage amps over 80RMS. We used a P500 where I used to work, in one of our audio studio's. I've read quite a bit of stuff on resolving grounding issues on the DH-200 but nothing really conclusive to me and yes, would really like some advice on grounding from someone with experience on this topic, I just find it interesting how much the dc offset drops just by grounding to chassis but are there side effects to this? Nov 2, 2008 · I've been a Hafler fan since I bought and built my DH-500 & DH-110 in 1981. Both were built from kits and are 100% stock. One is the Musical Concepts board. All good since I was planning on using my yamaha rxv1500 as the pre amp instead of the dh110. Can it be repaired with original mosfets at a reasonable price? Mar 21, 2022 · DH-500 or DH-220 (both have the same circuitry/driver boards, but the DH-500 is scaled up for more power). The problem is that I I'm not driving the amp nearly hard enough for this to be normal. This DH-500 came to me this way - powers on, switch light is solid, but does not come out of protection. At the end of the manual, it has the schematic, and parts list for the pc-7a. Hafler himself became disassociated with the activities. Oct 26, 2022 · I recently had a DH-500 on the bench with PC-10 boards. nifaron; Nov 8, 2008; Solid State; 3 4 5. I had never heard anything about it, but after searching it seems they are The Hafler Dh-500 is by far the most under rated amp ever designed and if you can get past it's very simply looks that lack the fancy lighted analog meters you get nothing but ultra clean power at unreal wattage outputs! Jan 16, 2015 · Hafler amps were said to be very good. relay clicks on, and as soon as I apply signal to the left side input, the R4 resistor I just replaced starts to overheat and Sep 24, 2024 · The Carver certainly delivers more power than the Hafler or your current Proton but "better" is very subjective. After a while of the light blinking and the fan running, it resumes. Nov 30, 2022 · The manuals for the Hafler amps are on HiFi Engine. Jan 6, 2018 · 1) The brand, Hafler, vs the man, Hafler: The Transnova series was the following generation from the original Hafler DH and XL lines. Dec 26, 2015 · This would be the board sold on Ebay. The sound is much improved. Hafler DH-200 & DH-101 options I'm a huge Hafler fan, I built my DH 110 & DH 500 new in 1981, the best grand I ever spent . Jan 12, 2018 · Not really familiar Hafler equipment and this one has me stumped. Adjusting the P2 trim pot, I can only get the bias down to 500 ma. May 5, 2016 · You can answer your potential buyer with, "Confirmed, all Hafler amps, including the DH-500 are common ground. But now I’m an owner of a set of AR-9’s that came with a Hafler DH-500 (tested at 452 watts into 4 ohm by Stereo Review. Hafler DH-500 Guidance. 375 seems like a good price, about 75¢ per watt. The green Nov 21, 2008 · The stock DH-500 is a good amp, but not a superb one. Was working great for the last 6 months, used it in an outdoor system driving some Infinity RS4B's. I also found out that the Jan 29, 2024 · I'm attempting to service this dh-500 and I am having a problem with the left channel. Procedure is the same and is what I used to set the bias at 350mA on my DH500 on a refurb project I did a while back. I have a DH-220 that's my "go-to" amp, whenever I need something powerful, reliable and good Nov 24, 2007 · AudioKarma Audio Forums. The fact that it's still around suggests it's OK. Jun 19, 2009 · I am having trouble with one of my Hafler DH-500 amps. Thread Hafler DH-500 problems ugh! DH500. Same Barracks, but across the hall, another Airman had a Sansui Integrated Amp also on Heresy's (I don't know what model). These issues presented as DC offset that could only be measured at the front side of the relay. The Left channel is good as I can adjust it anywhere between 50 and 550 ma. Thread starter dc270; Start date Mar 1, 2007; dc270 Now Off the Reservation. I cleaned the Mar 31, 2020 · AudioKarma Audio Forums. Hafler DH 500 . Look for a Melos, Cary, Audio Research, Conrad Johnson, vintage H/K Citation I, Sonic Frontiers, Quicksilver, Bottlehead or similar tube preamplifier. Nov 14, 2013 · Mounted in the same place as the DH-500, there were 'pouches' where mesh filters could be installed for long-term operation and keeping the interior cleaner of dust. Jul 8, 2007 · I've got a DH-500 (actually I have three, trying to make a nice HT setup) and one of the channels (yes, the RIGHT channel :-)) is out. The Hafler sounded more musical, the Sansui had more punch. Thanks in advance!! Jun 22, 2020 · But, got some more listening time with the DH 500. Anyhow, I've recapped it and changed the input to rca terminals and installed better line input cables. Replies 82 Views 9K Apr 29, 2020 · I've recently recapped an old Hafler DH-500. Since most consumer amplifiers made in the past 50 years are common ground, I'm not clear why a speaker manufacturer would produce a speaker with any unique Nov 26, 2016 · First problem I need corrected: I've had this DH 500 for 6 or so months and it seemed to develop a hum all of a sudden, more in one channel, but definitely present in the other. 8 VDC to trigger the protection relay. The boards are essentially the same. Does anyone have the earlier manual or the schematics? The board is in pretty good shape so I think I can read all the resistor codes, but the diodes are all most all dead and I want to be careful and sure. Those amps were sold both as kits and factory assembled. For some reason the DH 500 manual does not state how to set/adjust bias, but the DH 220 manual does. Hooked it up and it sounds great, very powerful and smooth, running it with an Anthem Pre 1L. Further down the hallway was a good ol' boy with DH110/500 and Cerwin Vega D-15s (Gray cabinet). I have MOSFET amps using the same devices (and probably similar circuitry) that Hafler used, though I've never heard the DH-500 specifically, and I owned a Dyna 400. I've read a few posts about ensuring the relay clicks when the amp it switched on (it does) and all fuses inside and the back are not blown. Jul 11, 2015 · I have a Hafler DH-500 in my attic. The pre amp was sold as a intermittent problem of one channel at times having problems and the amp as working good. I would like to change the bridge rectifier. Aug 23, 2023 · I have an older Hafler DH-500 with a PC-9A power board instead of the PC-9C that I have found on the online manuals. levier; Apr 13, 2023; Solid State; Replies 8 Views 469 Nov 4, 2018 · I purchased a hafler dh-500 amplifier today with a matching dh110 pre amp. :sigh: May 24, 2024 · Got this guy in protection, one channel is spitting out -12V. Jan 29, 2015 · AudioKarma Audio Forums. The design uses all modern day parts, dual complementary jfets from Linear Integrated Systems for the input stage (IPS), the jfets are cascoded into current mirrors, 2T push-pull VAS (voltage amplifier Nov 9, 2008 · I have a Hafler DH-500 that is giving me trouble. I worked on getting the speakers usable Dec 6, 2013 · Just picked up a Hafler DH-500 power amp from CL at a good price for my secondary system. dh-500 manual Mar 27, 2021 · AudioKarma Audio Forums. The other is made by a company called Qua Co that seems to only sell on Ebay. It’s worked flawlessly until a couple weeks ago when I turned it on and got nothing. Probably a recap, and then the transistors, since I have PC10 boards. Last night, the amp cut out and the red on/off switch started blinking. I have said many times it's the best (just under) grand I ever spent! It finally fell victim to a lightning surge a few years back, one of these days I'll fix & upgrade her. I replaced it and powered on the amp. Before making the plunge, checking to see the basics are good. Apr 13, 2018 · It's the pro version of the DH-500. That's when Mr. Discussion in 'Solid State' started by ivandezande, Aug 29, 2022. Anyhow, been listening to some jazz, in particular, the LA 4. Jul 11, 2015 · I have a Hafler DH-500 in my attic. The DH-200 along with a DH-101 was my first component system. Runs barely lukewarm, with the fan running normally. But last week it started Jun 4, 2023 · Hi just purchased a Hafler 500 amp. Now, I'm looking at a company on ebay to upgrade/rebuild my DH-500 and matching Hafler pre-amp. Anyone have a schematic (complete service manual) of the P225/230?, we know it uses the PC-19c pcb, so assumptions are it is the exact same as the DH-220. All fuses are intact. Mar 1, 2022 · AudioKarma Audio Forums. This helped to protect the speakers in addition to the relay's function of delaying the connection of the speakers to the amp outputs. Mar 1, 2007 #1 Apr 1, 2020 · BTW myself and Bob Cordell have designed a new pcb set for the DH-200,DH-220,P225,P230, working on testing them out for the DH-500 as well. I have a Hafler DH-500 that sounds fine but has a 60Hz hum coming from the chassis that is noticeable at low volumes. The red light is on and solid (not flashing) and I noticed that the relay didn’t click. There is no hum on the output, just a hum from the chassis. Plan is to upgrade most of the amp with Musical Concepts driver boards and power supply, etc. It's a bit unusual in that it has the pc10a version of the boards which don't quite match the manual available online. The Left/Right gain knobs, and the 1/4" headphone input jacks are the main differences. The Hafler DH-500 power amplifier is a “big brother” to the company’s widely acclaimed DH-200, embodying many of the same design concepts with a thorough reengineering to deliver high-power performance with high reliability. It beats my former Adcom GFA-555 hands down. I am reading that you are building a Hafler DH-500 from parts, is that right Nov 10, 2018 · OK, I know I've asked this before, but I've been collecting vintage receivers and lost interest in my DH-500, at least for a while. There are two kits that I have found that are available for the main boards. Today, I turned the amp on and it May 17, 2007 · Given similar prices, go for the Hafler. After a few minutes the amp was operational and worked without issue until I yearned it off 90 minutes later. But I am having trouble adjusting the bias on the Right channel. there is a 47k 1/4 watt (R4) that is open. But - this is a Musical Concepts modded unit, dual toroids, way bigger caps, etc. I have a Hafler DH-110 and a DH-220 as backup spares. 00 a pair. The light is normal on the front of the unit and the fan is Dec 23, 2010 · DH-110's go for ~half of your budget. ryuuoh FFXIV Summoner. Mar 1, 2007 · AudioKarma Audio Forums. Replies 83 Sep 4, 2009 · After being driven a while, my Hafler DH 500 (~1980, kit-built) is going into thermal protection mode. Aug 29, 2022 · Audiokarma Home Audio Stereo Discussion Forums. Mar 3, 2015 · A lot of DH-500 owners, over at DIYAudio, have been recommending an ADCOM 100V 18000uF Computer Capacitor. Page 1 of 2 1 2 Next > Feb 17, 2024 · I'm not trying to say that this isn't exactly rocket science, as that wouldn't be fair; back when I was doing this all the time the transistors involved on the scamp board in the DH-500 were all so cheap and available that it was more economical just to replace 'em all--along with any suspicious other components--and be done with it, rather Nov 28, 2020 · In 1985 I purchased the DH-110/220 to go with my Heresy's. I have no trouble adjusting the DC offset down to 0-2 Mv on both channels. Does anyone have a suggestion on where I should start my amateur trouble shooting? Thanks very much. Sep 6, 2007 · How good is hafler power amps? I have a chance to pic one up and also a hafler pre-amp, both for two hundred bucks--is this worth it? there both mint and work very good, i like the fact that it's 255 watts per channel, I have never owned hafler before, is it high end? is it worth 200 bucks for Jan 7, 2008 · After I measured the DC offset on my "new" Hafler Dh-500, I found that the left channel was ~100 mV and the right was ~500 mV. I would generally agree that it is more cost-effective to buy more CDs, better speakers, or room treatment for your listening room. Solid State . While I LOVE the looks of my old vintage receivers, I don't think most will match the sound of the Hafler. :worried: I did some searching and reading, and apparently according to the manual, it takes 1. Very easy to work on, all parts are easy to replace except for the output MOSFETs which are NLA. Now known as AudioXpress, the reprints are available from Old Colony as well as a compendium in book form. I was getting really odd voltage measurements and current measurements at the rail fuses. Solid State Hafler DH-500 Bias Procedure. It was also when the brand, Hafler, was sold to Rockford/Fosgate. Hafler DH 500 Refresh and Offset Issue Hafler DH 500 early version. Apr 13, 2023 · I recently purchased a working DH 500 with early PC 10A driver boards. I've looked at several other threads about this same topic, but I'm not having much luck. Otherwise, the chassis, driver boards, heatsink, speaker relay, and power supply components were exactly the same as the DH-500. Perhaps you can help us here by giving us more details about what you are doing. I just bought a DH 500 and I intend to mod it. For $1K+, I'd be looking for an Audio Research or Conrad Johnson tube preamp. However, DAC, amp, and preamp also influence the final result. Aug 6, 2011 · Wiring is fine as per manual, thanks. It sounds great with my VTL preamp. The fan is audible when the music isn't playing, probably needs cleaning. Thread starter audio_exp; Start date Mar 1, 2022; Tags dh-500 haler audio_exp Member. This is the input coupling ecap, not much room in there to fit a 10uF film. An ARC SP-9MkIII is my daily driver as are my radically modified Dynaco MK-III mono tube amplifiers. There are a number of benefits that the XL-600 holds over the earlier DH-500/P505. I have one friend in the area that got one for his DH 220 and he loves it. Ouch. Sep 19, 2009 · The DH-200/220s had them and the P500 has them, too. Assuming that it was the relay I picked up a NOS relay on ebay and Apr 15, 2013 · If I were in the market for an older Hafler amplifier I would highly recommend the XL-600 over the earlier DH series amplifiers. Oct 11, 2009 · Would probably be more trouble than it is worth, but you could build up a pc-7a hafler board from scratch, on say a piece of perf board. So, today I pulled the cover and find a green wire disconnected from the relay, photo shows it well. I have a pair saved, but I want to rebuild my boards 1st. The AR-9’s are 4ohm) and my Vintage audio life will never be the same. Hafler DH-500 buzz/hum help Hafler DH-500 problems ugh! DH500. It's available on ebay (not mine) for $78. " As for why speakers _need_ a common ground amp, I'm still scratching my head. Jan 29, 2015 Don't get me wrong, a Hafler 500 still a GREAT amp, but you can understand why Mar 10, 2013 · The entire Hafler lineup of the DH-x00 series was addressed in a series of articles in Audio Amateur from the 80s. I've never owned or listened to the Carver or Proton but I did own a Hafler DH-200 for quite a while and a DH-500 for a short while. I’m sure it’s the small signal transistors, so I’ll get that sorted. And some amp board changes, and I’m not sure I like them or that they’re good Nov 9, 2008 · The proper repair technique is to put back together in original form. I'm surprised at how good this amp is. Dec 23, 2010 · The DH-500 is in a different league than the DH-110 that Hafler matched it with. I'm a bit surprised it is as different from the DH 200 as it seems, planning to plug the 200 back in for a more direct comparison. The XL-600/DH-500/P505 share the same transformer and have the same voltage on their DC rails. Caps look good with no bulging and the amp sounds fine when it runs. Nov 13, 2023 · Hello. tjl pwxanb kugab akkqgiu hjephv zufwv xqj ormwu xgajpgq fnf