Hafler DH-500/P500 Mods - diyAudio
网页2020年10月30日 · 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.
Hafler DH-200/220 Mods - diyAudio
网页2004-03-28 5:49 pm. #1. As suggested in "hafler dh-220" thread to repair it, here is the starting point of mods that peoples have done on this amplifier. So far in previous abovementioned thread, 2 mods were brought up: #1) Replacing the load resistors in input stage with current mirror. I believe that this mod would increase the open-loop gain ...
Hafler DH-220 - Taking apart a perfectly good amp - diyAudio
网页2024年1月16日 · The build is absolutely worth the effort, time, and consideration. Take apart that perfectly good amp, by all means. The DH-220C takes those old lateral FETs into the 21st Century. Bob and Rick obviously put a lot of time into the design and documentation. I will not part with my DH-220C.
Hafler DH-101 Preamp - diyAudio
网页2007年6月1日 · to the then current production parts list. It is. designed for all DH101 with Serial numbers. 1918999 and below. Eight parts as follows. For each channel: The original Q1 is MPS-A-18, replaced by NPN BC413C. The original Q2 is MPS-A-6523, replaced by PNP BC415C. The original R10, R11 are 100R 1/2W replaced by 47R.
How do I adjust DC offset and bias on my Hafler XL-280
网页2021年10月16日 · A dead Hafler XL-280. Two exploded 470uF caps hidden away in the power supply board. A completed repair using a Musical Concepts PS-200M power supply board. Great kit, instructions could use improvement, but overall a very good experience. Best part: after I got done with the repair the amp...
Hafler DH101 preamp repair and mods? - diyAudio
网页2006年4月29日 · 2006-11-15 2:33 am. #12. Upgrading Resistors. Sounds like the preamp runs with a fair amount of voltage to require. the use of 1/2 watt resistors. If you want to really get serious. . . replace with 1/2 watt metal film. . .the 1/8 watt resistors are. underpowered! The preamp is might be over designed to give.
Hafler 120 modifications - diyAudio
网页2007年10月15日 · The Hafler 9180 amp is a good one to study as you can see where in the circuit improved (polypropylene) film capacitors are used and locations where 1% metal film resistors are used. I am using two of these amps in addition to a DH-120 and can testify that, for example, the 9180's sound is more refined and detailed, especially in the upper mids ...
Hafler DH101 preamp repair and mods? | Page 6 | diyAudio
网页2006年4月29日 · Results are immediately, wide stage, dynamics, and of course the magic hidden details, simply to try and see the difference. Even John Hillig of Musical Concept in his super mode HAFLER DH 101 recommend removing input capacitors from preamp, all that matters is that you are sure that the power amplifier input coupling capacitor exist. D.
Hafler Transnova 9300 - diyAudio
网页2015年3月26日 · I discovered this scheme in the first Acoustat amp. Due to a negative/positive feedback, it had a very low output impedance. Indeed, the Hafler Transnova Series was designed by James Strickland, and was a direct descendent of his Acoustat TNT-200 and TNT-120 amplifiers. Transnova is an acronym for TRANS …
Hafler P230 troubleshooting - diyAudio
网页Member. Joined 2003. 2018-10-11 4:30 am. #3. > all four transistor bases should be at .22V. In my left channel those voltages were below 10mv. That does not sound right. If Ns and Ps could be matched, it would be zero. For typical difference between N and P, 10mV-20mV may be normal. "0.22V" may be a red-herring typo.