The Hafler DH-222 Bridging Kit is available to enable conversion of the DH-220 into a high power monophonic amplifier, bridging the two conventional channels into a single floating output which can deliver in excess of 400 watts into an 8 ohm load. Its rated power output is 350 watts across the audio band.A Stereo Power Amplifier available ready built or as a kit. Intended for 120 V AC 60Hz in the USA, for use in other countries a multi-voltage power transformer is available at extra cost for 100, 110, 120, 200, 220 and 240 volts 50 or 60 cycle AC mains.I have access to literally hundreds of thousands of Obsolete User Manuals, Lots of Repair Manuals, Service Manuals, Rare Schematic Diagrams, PDF Books, How to Repair Manuals, Lost Operating Manuals, Old Handbooks, Lost Parts Lists, Hidden Service Bulletins, Informative Repair Tips, Complete Disassembly Routines, and Much, Much, More!. I carefully scan and arrange each document into a downloadable and printable PDF FILE of high quality. It will take me years to scan and create all of the files I have access to. So if you use the search feature on our website and do not find your document simply use the Contact Form and ask for your document. More than likely I will have it. I will quickly scan and upload the file and then send you back a link so you can purchase.There was a time when my good friend Luigi was bringing HiFi gear by our house for testing on a regular basis. And although there were lots of interesting discoveries to be made, somehow the devices did not strike a chord with us to the extent that we actually wanted to own them. One day, as I was climbing up the staircase from an evening teaching classes, I could hear music playing in the living room that sounded very realistic, even from a distance. Whatever this is, I was thinking to myself taking the last few steps, this is going stay. The system Luigi had set up for us was a Hafler combo consisting of the DH-110 preamplifier and the 60 watts DH-120 power amplifier. And its musicality was beyond anything we had heard at the time. When I later asked my wife at which point she knew that this would stay, she said that she had already heard it was very special from the kitchen – which is about thirty feet down the hall.
We gave the Citation a final listen and then hooked up the DH-220 for comparison. The improvement in this scenario was immediately audible even though the amp was still warming up. The slight dreaminess of the Citation was gone, music now had a more intense and realistic dimension to it which became especially striking when playing live recordings. Whereas the Citation had caressed the listener, the Hafler had a straightness and insistence to it that was familiar to me from some Quad amplifiers. The DH-220’s midrange is tonally very accurate and at that pleasingly broad. Its bass lines are powerful and controlled which develops into a pleasing fullness of sound. Spatial representation is highly accurate and piano notes are flung deep into the room. The Halfer played so well that we were able to remove the weights that I had placed on top of each speaker for better imaging and could pull the speakers further into the room without losing foundation. We will certainly keep this amp around for a while to enjoy the new dimension in sound. The Hafler DH-220 is well worth exploring. Wherever this amplifier fits in, it is going to be very hard to beat.From my own experience I know that the DH-220 can be quite a princess, in the sense that it does not play with everybody. Some time ago we had borrowed it from Luigi to test it on our smaller system. In this scenario it had to play with some mediocre preamp and mid-fi speakers. The result was less than pleasing, and we soon returned the amp to look for something more appropriate. I was therefore surprised when Luigi insisted that I give this amp a second chance, now that all our other components had gradually been upgraded. In the current scenario the DH-220 was to replace the Citation Twelve Deluxe, a power amp that we have come to enjoy. And the playing partners were a Lenco L75 turntable, the Restek V1 pre, and Tannoy DC6t speakers at 8 ohms.
There are not many amplifiers capable of winning over our hearts from 30 feet away with such unanimous vote and certainly not at a price tag that most people are able to afford. Because of the obvious qualities of the Halfer, Luigi decided to purchase the 115 watts DH-220 and had it readjusted and fitted with new caps. The class-A portion of the amplifier was increased in the process, which has a positive impact on sound and leads to greater heat dispersion. I think you can literally fry an egg on this unit. At twelve kilos, the little amp feels like a solid piece of metal. The heat sinks are massive, and with this much class A-power that is probably good as it is. For an amplifier of this caliber, distortion figures are very low at any frequency. The below specs show THD at 1 kHz.
We understand the importance of online privacy and are committed to complying with the EU General Data Protection Regulation. To reflect our commitment, we updated our terms and conditions. By continuing to use Reverb, you agree to these updates, and to our cookie policy. Learn MorePA-7 Elite has great naturalness. The Elite version does a tremendous job. Then the Ultra ups your game with even better imaging, focus and delicacy. Superb sounding caps are used in the and front-end power supply. Feedback loop has Muse Audio-Grade caps on the PA-7 Elite for higher resolution, crystal-clear frequency extension, clarity and just plain naturalness. See Ultra build details in full mod description below.
PA-6 Elite has great bass, quick powerful transients, smoothness, natural warmth and great 3D imaging. That same word naturalness just keeps coming up. Though the Elite version does a tremendous job your Ultra ups your game with even better imaging, focus and delicacy.
You will receive a PS-220/500 power supply specialized for your amp, please specify your amp model when you order. See more PS-220/500 versions here, some of these items on Exotic Parts page. PA-7 V2 has had an extended ‘road test’. PA-7 V2 Ultra driver boards are now ready to install into Hafler DH-200/220, XL-280, DH-500 and XL-600 amps. Introductory price: Same As original PA-7 Ultra for now. See prices below. You will receive a PS-220/500 power supply specialized for your amp, please specify your amp model when you order. See more PS-220/500 versions here, some of these items are on Exotic Parts page.The PA-7 V2 Sound: This is no mere Hafler. No, we don’t demean this great basic amp design which so many still love. Still the music lover ‘ear’ always wants more. PA-7 V2 is a great amplifier in a Hafler chassis. The word fidelity is a really big, not just a marketing term. You want to feel a connection to the vocalist and background vocalists too. You want to hear instruments in a striking way. You want much more of true tonal structure and timbral clarity of each instrument. Voices are clear, full-bodied and so intelligible that emotion is conveyed in the performances at a new level. You feel the mood, the intensity of the performer. Many will hear ‘new’ background vocals singing along with the lead vocal or the multi-layered vocals of the performer overdubbing ‘background’ vocals. There is a sense of gut solidity, simple majesty and air-moving power that must be heard. If your speakers play deep you’ll be thrilled. PA-7 modified Hafler amps will easily compare to the finest sounding amplifiers available today.
Our PA-7 V2 Ultra mod is truly State of the Art and beyond State of the Art in sound as it is offered by so-called high-end manufacturers. Although we at Musical Concepts have modified many expensive well known amplifiers we’ve never seen build quality close to the Ultra. The superb Takman resistor is used in nearly all slots for all Ultra driver boards. For all amps the Ultra also includes a new high in-rush current, silver-alloy power switch and a upscale IEC power cord socket with hi-current cord. Just imagine what this incomparable product might sell for if it had some fancy over-hyped manufacturers name on the front panel. This is the finest mod we have to offer.
The planning and hopes for any mod result will depend to some degree on the underlying health of the original amp. Consider these helpful improvements.
The Design: Our designer John Hillig has refined the PA-XX series modifications over many years. This research created new circuitry enhancing clarity and transparency without brightness or ‘etching’ i.e. that ‘forced detail’ sound you probably know too well. With a laser focus we fashioned a new path to a new level of excellence.The planning and hoped for results with any of our mods will depend, to some degree, on the underlying health of the original amp. Consider these helpful improvements.
The PA-7 V2 is a tweaked-by-ear amplifier circuit. MOSFETs, the OEM Hafler output devices, are very easy to drive. A traditional higher current, Class-B driver stage, is not required resulting in a simpler Class-A transconductance stage(VAS) which does a great job. We used wideband video transistors for their minimal loading of the input stage. They also need only a minimum of compensation.
Because MOSFETs are very easy to drive a traditional higher current driver is not required so a simpler Class-A transconductance stage can do a great job. We use high-performance low capacitance video transistors. Also since MOSFETS don’t experience ‘thermal runaway’ there is no need for volt-amp limiting circuitry further simplifying the design and enhancing clarity. Your ears will agree that ‘simple is good’.Okay all you guys who bought PA-7s please calm down. PA-8, for Hafler DH-200, DH-220, XL-280, is a physically larger PA-7 with directly mounted power mosfets.We have given short shrift to these amps so let us begin to remedy that. The PA-XX series mods will work fine in Pro Series amps such as the P500(not PA-8), P225, P230 and so on. The kit prices will be unchanged, but some of the amps require more labor, i.e. installed prices go up. Other modifications touted for the home versions work quite well. At present our instructions are more tuned for the home versions of amps.
The PA-6 is an enhanced, effective tweaked-by-ear amplifier circuit An enhanced front-end power supply design, called CRC, inherited from PA-5 series with four front-end power supply caps provides a much cleaner, quieter voltage for the critical front-end circuitry.Superb high-end audio grade caps are used in the feedback loop and front-end power supply positions on the PA-6 Elite for higher resolution, crystal-clear frequency extension, clarity and just plain naturalness. See Ultra build details in full mod description below. These kits includes additional installation parts including hookup wire, solder, capacitors, etc.
