Tube Integrated Amplifier

Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC

Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC

Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC    Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC
This is a very nice Harman Kardon A500 tube integrated amplifier, serial #5768271. See feedback on my amps at the end of this listing. For those of you that have followed my listings, you may have noticed that the prices are creeping up. I see the main reason for this to be the resurgence in appreciation of vinyl and tube amps, and consequently the cost of'raw material' for restorations has increased rather dramatically. This is an HK A500 integrated stereo amplifier from the golden age of tube amps.

I had an HK A300 in college many years ago and was always impressed with its sound. So--as much for a hobby as anything, I researched these Award Series amps with the intent of updating them to make them safe and reliable.

I have been very focused in my efforts. I never put power to these amps without first replacing the power supply electrolytic and paper/oil coupling capacitors.

The restoration of these and any other 60 year old tube radio, tuner amp, etc. Per the experts includes replacing the electrolytic and signal coupling capacitors. These specific capacitors do not age well, and it's generally agreed that recapping is an essential requirement if you want to keep a tube unit reliable and safe.

Some people believe that'reforming' capacitors (bring them up to voltage with a variac over a few days) will provide safe operation, but I would rather use new capacitors even though that is a much more expensive and labor intensive route. Interesting enough, most the other components tubes, transformers, wiring, most resistors, coils, etc. Do not generally fail with age. Switches and potentiometers volume, tone, balance, etc. May become noisy, but usually can be restored with proper use of quality cleaning (DeOxit) solutions.

I believe it should be the intent of restoration to bring the amp back to the quality and sound of the original unit as originally designed by the HK engineers and I have selected the components to match the original design with one exception. There have been improvements in rectifying diodes since these units were first built, and that's one area where I provide an upgrade. New diodes, with fast turnoff /soft recovery are now available and because of their characteristics, provide a cleaner rectifying operation than the original diodes--fear not, the "tube sound" is not diminished in any way with these diodes--only a cleaner power system. Proper restoration of the A500 is extensive.

There are a total of 24 electrolytic and coupling capacitor sections to be replaced. In addition, the A500 has adjustable output tube bias balance circuits consisting of fixed resistors and potentiometers.

Before I undertook the A500 restorations, I reviewed my plans with the "recognized HK expert". He indicated that these pots and resistors should be replaced as part of the restoration as they are too critical to take chance on possible future failure. The bottom cover was removed for pictures. After recapping, I have verified all the B+ voltages to be within original specifications.

This particular amp was partially restored by a very skilled tech before I bought it. Essentially everything he did was essentially the same as I do. After I received this amp, I did some additional work, but it was a nice candidate when I bought it. In addition to replacing the electrolytic and coupling capacitors, (using premium Sprague/Vishay 716 caps for the non phono pre-amp coupIing and Russian K42Y Paper-in-oil caps for the power tubes), have tested all the tubes on my B&K 707 tube tester and replaced any that were marginal. The four output tubes are a performance matched GE 7355 set.

Appearance condition : The condition is very nice with some minor exceptions. The chassis top is decently clean, has three small stains near the vertical front shield. Some time ago a previous owner attempted to clean a portion of the faceplate, the area below the RH knobs has a slightly cloudy appearance. This is either noticeable or disappears depending on the lighting. All the lettering on the faceplate and chassis is legible and clear.

The knobs are all good, they have been refinished, and the inside of the chassis, which is important electrically, has no issues. It's difficult to show the true color of the amp, it's essentially an off-silver color. I think the outdoor pics capture the color best. Also, the on-off button photographs blue, the actual color is the correct HK violet.

The plastic pilot lamp is really violet, not blue as it looks like in the picture. ALSO, AFTER THE PICTURES WERE TAKEN, I REPLACED THE CHEWED UP AMBIENCE CONTROL KNOB WITH A NICE CORRECT MATCHING ALUMINUM KNOB.

As mentioned above, the A500 has a bias balance feature for the output tubes. When properly set, each output tube carries the same amount of load. Some tube amps have built in meters to set the bias balance--not present on the A500's so the procedure has been either to use a intermodulation distortion analyzer (not at all common) or to measure inside the unit with the bottom cover off. I don't like doing that with high voltage nearby.

So, I ran the points to test jacks on the chassis to allow setting the bias balance with the unit buttoned up. The potential on the test points is safe--less than +/-10 volts. This should be done whenever the output tubes are changed, or every 100 hours or so of operation.

As the line voltage these days tends to be somewhat higher than in the 1960's I've added a thermistor inside the amp to slightly reduce the internal high DC voltages. Bring it closer to what it would see when new.

Work performed on this A500 consisted of. Replaced all of the coupling and electrolytic capacitors--not because they have failed, but to increase reliability and bring the unit back into specifications. Capacitor failures can ruin your day (and your equipment). Replaced the power supply rectifying diodes with modern diodes that perform the identical function, but with less noise.

Tested all the tubes on my B&K 707 tube tester and replaced all tubes that did not test strong. Cleaned all switches, controls and tube sockets with Deoxit cleaner--D5 for tube sockets, switches and contacts, Fader F5 for the potentiometers. Verified all controls, B+ voltages and operations.

Replaced the bias control pots and resistors. Replaced the pilot lamp with a LED. Added bias balance set test points and provided a meter to set the bias balance. Added a voltage reducing thermistor to slightly lower the internal voltages. Ran amp for a minimum of 16 hours after restoration--with no issues.

If you are reading this, you probably are familiar with the "tube sound". It's just mellow, and clear and wonderful (my opinion).

The HK tube amps were (and are) highly respected units from the'golden age' of tube systems. Probably says something for HK in that they are one of the very few hi-fi manufacturers from the 60's that are still in business. The main specs of the A500 are. IHFM music output power: 25 watts per channel. These tube amps really like high efficiency speakers, many folks use Klipsch speakers with efficiencies in the 90-95 db range, I personally like the Electrovoice TRX12B's. How much power you need also depends on your room size and listening style. 5 db 12-35,000 cps at normal listening levels. Output impedance: 4, 8 and 16 ohm. Stereo inputs: low level 2.5 mv. For magnetic phono cartridges and tape heads (from tape recorders). Stereo inputs: high level 200 mv. This is suitable input for tuners, CD decks, ECHO Dot and most mp3 players, tablets and smart phones. Third channel output with volume control (called ambience): to feed a center channel amp, reverberation unit remember those? Stereo tape out--to feed a tape recorder. Headphone jack--does not disconnect power to the speakers when in use. Separate Bass and Treble controls for each channel--more knobs to turn. This is not your son's amplifier.

This is a tube unit, and as such, has voltages inside the chassis that can be lethal, 350+ volts. Tubes and transformers get hot and while the unit is rated for a 100% duty cycle, I suggest turning it off when not in use. My goal was to make this amplifier as safe and reliable as I know how to without losing the wonderful "tube sound".

I believe I have accomplished this. So, if you are into tubes, or just starting, here is an amplifier for your consideration. If your country is not listed, contact me, maybe we can work something out. I've not had that issue, but want to state my position.

Harmon Kardon A300 Refurbished Tube Amplifier (#230229344793) I cannot explain how wonderful this amp makes my music sound!!! Harmon Kardon A300 Recapped Tube Amplifier (#330277726387) Impressive! Packed like a true engineer! Got me, the amp flew me. Harmon Kardon A300 Recapped tube amplifier, 12AX7's (#230219839832) Great communication, packaging, friendliness, helpfulness.

Harman Kardon A300 tube amplifier refurbished HK nice (#330388638348) While you guys were sleeping I got a great deal on a true tube amplifier. Harman Kardon A30K A300 6V6 tube amplifier refurbished (#230403490711) Here is a very honest good man Thank-you!

Harman Kardon A300 tube amplifier refurbished HK nice (#230414716217) Item as advertised, great communicator, outstanding packaging, A+++. Harman Kardon A300 tube amplifier refurbished HK (230433088703) Amp arrived today, Hooked it up and it works fine, sounds good. Harman Kardon A300 tube amplifier refurbished HK nice+ (#230426845298) First rate all of the way. Harman Kardon A300 tube amplifier refurbished HK sharp (#230437780607) Very nice unit, Top ebayer.

Harman Kardon A300 tube amplifier refurbished HK nice+ (#330425822207) Very well packed, amp exactly as described. Harman Kardon A50K Refurbished Tube Amplifier A500 HK (#230469196743) A really beautiful job of restoration. Harman Kardon A300 tube amplifier refurbished HK nice (#230471466536) Thanks camaroguy62 you made a 62 year old guy happy. Very good follow up and best communication!

Harman Kardon refurbed A30K A300 tube amplifier 7408's (#230586591434) The real deal here, great amp.... Harman Kardon A300 tube amplifier refurbished 7408 nice (#230580499849) Great amp.

Harman Kardon A500 Refurbished Tube Amplifier, HK (#230582037624) Very nice unit as described... Thnks fo deal (Note: sent to Russia).

This is someone to trust! Harman Kardon refurbed A230 stereo tube amplifier EL84 (#330539388127) Outstanding. Vinyl can now be played in perfect mode.

Harman Kardon refurbed A30K A300 tube amplifier 7408's. Harman Kardon refurbed A300 tube amplifier 7408's, 6V6 (#230624946073) This is one incredible sounding amp! Harman Kardon A300 (A30K) refurbed to orig. Harman Kardon A300 refurbed to original, integrated tube amplifier 7408 tubes (#330658656112) Excellent Top notch Ebayer! Harman Kardon refurbed PC200 integrated mono tube amplifier pair 6BQ6 / EL84 (#330657312751) Fantastic amps! I'd give 6 stars if I could! Harman Kardon refurbed PC200 6V6 integrated mono tube amplifier pair (#230721008973) All E-Bayers should be this good. Need more room to tell how good. A++++++ ^^ (Note: Sent to Hong Kong). Harman Kardon refurbed A224 integrated stereo tube amplifier EL84/6BQ5 beauty! (#330684623823) What can i say... Camaroguy is simply a true gentleman!!!

Harman Kardon A300 refurbed to orig integrated tube amplifier 7408 tubes beauty! (#230782913856) Very generous with info/details about item. Packaging went one step beyond.

Harman Kardon A500 Integrated Tube Amplifier, Refurbed to orig. Specs 25WPC (#330734051861) Absolutely the best amp I've ever owned. Harman Kardon A500 Integrated Tube Amplifier, Refurbed to orig specs 25WPC beaut (#330742827034) A+++++++++++++++++++++++++++++ Harman Kardon A300 refurbed to orig. Integrated tube amplifier 7408/6V6 beauty! Harman Kardon A300 refurbed to orig.

Integrated tube amplifier 7408/6V6 nice! Harman Kardon refurbed A10 vintage mono tube amplifier EL84, pair available, #1 (#230752879119) Bought again.

Harman Kardon refurbed A10 vintage mono tube amplifier EL84, pair available, #2 (#330836261774) Good. Integrated tube amplifier, K40Y-9 PIO caps (#330852079075) the very best!! Harman Kardon A30K (A300) refurbed integrated tube amplifier, K40Y-9 PIO caps (#330877006072) Great guy and excellent working unit. Everything he said it was.

Harman Kardon A50K Integrated Tube Amplifier, Refurbed to orig. Harman Kardon refurbed A220 integrated stereo tube amplifier 6V6 outputs (#230934331966) Great sounding stereo! Harman Kardon A30K (A300) integrated tube amplifier, refurbed to orig. Harman Kardon A300 integrated tube amplifier, refurbed to original, nice unit (#330896129005) I have never received anything that was packed this good. Harman Kardon A300 refurbed integrated tube amplifier, K40Y-9 PIO caps, nice amp (#330901386193) Packed very good, sounds great and works like a champ, my first tube amp. Harman Kardon A300 refurbed integrated tube amplifier, nice amp. (#230980302576) A+++++ everything was as described phenomenal customer service. Harman Kardon refurbed A230, 15WPC, EL84/6BQ5 integrated stereo tube amplifier (#230991580545) Thank you. Harman Kardon refurbed Prelude PC200 integrated mono tube amplifier 6V6 outputs (#231003877976) Carefully wrapped and boxed. Packaged so well it could have been air dropped.

Harman Kardon A30K (A300) refurbed integrated tube amplifier, 7408 (6V6), nice (#231013537159) Amp is great! Just as described, very good communication, Recommended! Harman Kardon A500 integrated tube amplifier, refurbed to original 25 WPC, nice! (#231103795100) Extremely Satisfied Exactly as described.

Harman Kardon A300 integrated tube amplifier, refurbed to orig. K40-9 PIO caps (#231113685092) A+. The packaging, communication and of course the A300...

Harman Kardon A30K (A300) integrated tube amplifier, refurbed, K40-9 PIO caps (#231123278867) Amazing amp! Packaged well, sent out in a timely way! Note: Sent to the Russian Federation.

Harman Kardon A300 refurbed integrated tube amplifier, K40-9 PIO caps, beauty! (#231129361216) Couldn't have been a better experiance. Harman Kardon A224 integrated stereo tube amplifier, refurbed nice vintage amp (#231159509912) 6 stars if I could! Could not be happier - I love, love love this amp! Harman Kardon A300 refurbed integrated tube amplifier very nice!

Packaging and followup assistance was beyond expectation. Harman Kardon A300 refurbed integrated tube amplifier, Russian K40-9 PIO caps (#231166554536) Arrived promptly, very well packed. (2) Harman Kardon refurbed tube A10 amplifiers, pair for stereo, 6BQ5 / EL84 (#331134127349) Wonderful service from Tom. This guy goes above and beyond and does quality work. Harman Kardon A300 refurbed integrated tube amplifier K40-9 PIO caps nice amp!

(#231410935476) The A300 is wonderful. I will cherish and enjoy it for many, many years to come. Harman Kardon refurbed tube A10 mono amp 6BQ5 / EL84 pair available for stereo (#231431551216) Nice vintage piece + documentation from H-K guru.

Harman Kardon refurbed tube A10 mono amp 6BQ5 / EL84, nice amp (#231452883418) Perfection in every way. Harman Kardon A50K (A500) integrated tube amplifier, refurbed, nicest A50K ever? Refurbed Harman Kardon A230 stereo integrated tube amp, amplifier, EL84 15WPC (#231508063897) excellent all the way!!! Careful professional packing, Thanks for all your effort.

Refurbed Harman Kardon A230 stereo integrated tube amplifier, 6BQ5/EL84 15WPC (#231684860285) Arrived quickly as described. Harman Kardon A230 refurbed stereo integrated tube amplifier, 6BQ5/EL84 15WPC (#331675385537) exactly as described thank you.

Harman Kardon A224 refurbed stereo integrated tube amplifier, EL84/12AX7 12WPC (#331694013884) VERY HAPPY with this HK A224 amplifier- thank you AAAA++++. Harman Kardon refurbed A12 integrated tube amplifier pair for stereo EL84, 12AX7 (#331691448725) Ebayer serio e professionale!!!!!! Prodotto perfetto Note: Sent to Italy. Harman Kardon A230 refurbed stereo integrated tube amplifier, 6BQ5/EL84 15WPC (#231747746533) wonderful piece..... Harman Kardon A500 integrated tube amplifier, refurbed to original, 25 WPC nice!

Harman Kardon A224 refurbed stereo integrated tube amplifier, EL84/12AX7 12WPC (#331761566635) Prompt, packed well, very friendly. Harman Kardon A224 refurbed stereo integrated tube amplifier, 12WPC, EL84/12AX7 (#331781059630) I REALLY think camaroguy62 is better than 5 stars! HK = labor of love for him. Harman Kardon A500 integrated tube amplifier, refurbed, 25 WPC, beautiful!

Harman Kardon A50K A500 integrated tube amplifier, refurbed, 25 WPC, beautiful! (#331790711087) Fantastic item as described. Quick to arrive and info included as directed. THQ Note: Sent to England. Harman Kardon A300 integrated tube amplifier, refurbed to original, 15 WPC, nice (#231878915940) most honest, knowledgable & trustworthy amp salesman in USA.

Harman Kardon A224 refurbed stereo integrated tube amplifier, 12WPC, EL84/12AX7 (#331834352822) Great ebayer. Harman Kardon A300 integrated tube amplifier, refurbed to original, 15 WPC, nice! Harman Kardon refurbed A230 stereo integrated tube amplifier, 6BQ5/EL84 15WPC (#231938247257) Great item. Thanks for doing what you do.

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Harman Kardon A30K (A300) integrated tube amplifier, refurbed to original, 15WPC (#332028707955)??????? Note: Sent to Russia, translates to? Harman Kardon A300 integrated tube amplifier, refurbed to original, 15WPC, HK (#232171304741) Cool amp. Harman Kardon refurbed A230 stereo tube integrated amplifier, 15 WPC, EL84, nice (#232170341076) Piece just as ordered! Harman Kardon refurbed A230 stereo tube integrated amplifier, 15 WPC, EL84, nice (#332071983696) Amp arrived very quick.

It works great and is exactly as described. Harman Kardon A30K (A300) integrated tube amplifier, refurbed to original 15WPC (#332074331908) Awesome amp. Harman Kardon refurbed A230 stereo tube integrated amplifier, 15 WPC, EL84, nice (#332093319677) Very positive experience!

Harman Kardon refurbed A230 stereo tube integrated amplifier, 15 WPC, EL84, nice (#332118903902) Very nice amp!! Harman Kardon FA3000X integrated tube receiver, has HK A300 amplifer section (#332117309696) Tom is certainly one of the most thorough and professional I've ever come across.

Harman Kardon refurbed A230 stereo tube integrated amplifier, EL84, 15 WPC, nice (#332134739752) great ebayer, good packing. Harman Kardon A50K (A500) integrated tube amplifier, refurbed to original 25WPC (#232255692922)???????

Note: sent to Russia, translation; Thank you! Harman Kardon A50K (A500) integrated tube amplifier, refurbed to original, 25WPC (#232296700982). Great Amp and very helpful after the sale! Harman Kardon A50K (A500) integrated tube amplifier, refurbed to original, 25WPC (#232362784954).

Harman Kardon A300 integrated tube amplifier, refurbed to original, PIO's, 15WPC (#232440204010). Having a few issues and Tom is being over-the-top helpful. Harman Kardon refurbed A230 stereo tube int egrated amplifier, 6BQ5/EL84, 15 WPC (#232459578678). Wonderful guy to work with!! Harman Kardon A300 integrated tube amplifier, refurbed to original, PIO's, 15WPC (#232558496376).

The best, stands behind his sales. Honest and excellent on all fronts. Harman Kardon refurbed A230 stereo tube integrated amplifier, 6BQ5/EL84, 15 WPC (#232530525588). Very fare ebayer, great communicator. Harman Kardon A300 integrated tube amplifier, refurbed to original, 6V6, 15WPC (#332487693158).

Harman Kardon Curchill integrated tube receiver, level 1 restoration, 15 WPC 6V6 (#232602205926). Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC (#332487614963). Harman Kardon refurbed A230 stereo tube integrated amplifier, 6BQ5/EL84, 15 WPC (#332537019443) Item is as described.

Great item, well packaged and super communication. Harman Kardon refurbed A220 Lute stereo tube integrated amplifier, 6V6, nice amp (#232799012341) This was BETTER than new & camaroguy can't do enough for U. Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC (#332661769919) Awesome product. Unit was super well packed and clean as a whistle. Harman Kardon 50K (A500) integrated tube amplifier, refurbed to original, 25WPC (#332860260557) Perfect.

Harman Kardon A30K (A300) integrated tube amplifier, refurbed to original, 15WPC (#332977672035) Best communication and the packaging was thoughtful and awesome. Harman Kardon A30K (A300) integrated tube amplifier, refurbed to original, 15WPC (#333051234508) Great Amp. Harman Kardon A230 integrated tube amplifier, refurbed to original, 15WPC, nice (#333150676727) Excellent. Harman Kardon A50K (A500) integrated tube amplifier, refurbed to original, 25WPC (#233241670239) great working condition. Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC, nice (#333357154652) The unit was perfect. Tom is the best and goes out of his way. Harman Kardon A300 integrated tube amplifier, refurbed to original, 15WPC, nice (#333383674483) Everything was wonderful. Great customer service and a magically sounding amp.

Harman Kardon refurbed A224 stereo tube integrated amplifier, 6BQ5/EL84, 12 WPC (#233442710884) VERY NICE PACKAGING! Harman Kardon A300 integrated tube amplifier, refurbed to original, 15WPC (#233450559834) Had an issue. Prompt, great service & assistance. Harman Kardon A300 integrated tube amplifier, refurbed to original, 15WPC nice (#233476894120) Tom has done a great job of restoring this amp.

Harman Kardon refurbed A230 stereo tube integrated amplifier, 6BQ5/EL84, 15 WPC #. Harman Kardon A300 integrated tube amplifier, refurbed to original, 15WPC 6V6 #. Excellent, just as described, very fast, very helpful. Harman Kardon A50k / A500 integrated tube amplifier refurbed to original, nice #. Packaged well, works and sounds great.

Harman Kardon A224 integrated tube amplifier, refurbed to original, nice amp (#233668441789) Amazing care and diligence. Harman Kardon A224 integrated tube amplifier, refurbed to original, nice amp #.

Beautiful, expertly refurbished amp, terrific, attentive service. Harman Kardon A230 integrated tube amplifier, refurbed to original, w/case. Harman Kardon A230 integrated tube amplifier, refurbed to original, 12AX7, EL84 #. Super NOTE: Sent to S.

The item "Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC" is in sale since Thursday, December 31, 2020. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "camaroguy62" and is located in Fenton, Michigan. This item can be shipped worldwide.

  • Model: A500
  • Country/Region of Manufacture: United States
  • Country of Manufacture: United States
  • Type: Integrated Amplifier
  • Brand: Harman Kardon


Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC    Harman Kardon A500 integrated tube amplifier, refurbed to original, 25WPC