Heath AA-2500 and AP-2510 Test

[@kowaltoboggan]

I really appreciated seeing this video and how you didn’t mind showing the importance of cleaning the controls. You could have edited that out, but instead included a great reminder for many a meaningful lesson for the rest of us. Looking forward to more of your content in 2025!

[@jeffreyhaynes5774]

Always check the simple things first. Words of wisdom from an x audio bench tech.😮I like the work you are doing keeping the vintage audio going.

[@Bubba24]

You did a great job with this video! Mistakes are the best teachers and the “never forgetters”!!! Don’t be so hard on yourself, we’re only human. We going to keep making mistakes in life. I really like your channel and enjoy watching what you endeavor into. Happy New Year to you and your family. God Bless You and keep up the good videos.

[@bmboldt]

I have a few vintage receivers, but my primary system is a mid 80s Yamaha C-60 and an M-60. Not as cool looking as a silver face receiver, but it's got that black face with the red lights and meters and it sounds good. We all make mistakes fixing things and we all learn things from our mistakes. The key is you didn't break anything. I once spent hours trying to figure out why I wasn't getting sound until I noticed the tape monitor was on.

[@kikurass322]

I too run the Yamaha C-60, lovely pre-amp, mine is running 2X Hitachi HMA 8500MKII's and 2X Hitachi HMA 7500MKII's all four are running BTL I can break windows at will :)

[@ewoutbuhler5217]

Yes, same exact thing happened when my dad got his first CD player early 80's. Connected it to aux on his Technics receiver, the Pioneer HPM-100 speakers remained dead silence. Messing with volume, silence. I was a little kid and on top of it. I suddenly saw the monitor switch set to Tape 1, so I reached out and flipped the switch. The room suddenly burst into the very loud and clear sound of Dire Straits. My grandparent jumped inches from the couch. Good memories!

[@jeffberwick]

Don't beat yourself up for ignoring your own advice about cleaning the controls. I certainly appreciate honest videos with mistakes far more than some perfected polished magical repair sequence. Also you learn more that way, right? -And so do your followers. Keep it up in 2025. Looking forward to more great content.

[@_WyreTheWolf]

Nothing is a failure if used as a teachable moment.

[@mnewln1800]

It's being "taught" the same lesson repeatedly that sucks!

[@davidbailey6350]

Failures are the greatest teaching moments in life…. At 70 yrs I’ve made a ton… Such is Life….. All in all, great video….

[@007fredh]

Aiden, thanks for taking the time towards the end of the video for your opinion on how the Harmon Kardon works compared to an older Marantz receiver. So many KZbinrs are scared to give their opinion. Happy new year to you and yours.!🎉

[@MarkEversoll]

Small point. I built and used many Heathkits (including the AR-15 and an AA-15.) The kits come with a comprehensive assembly and service manual. So when seeking service information for a Heathkit product that was offered as a kit, one can also search for the assembly manual you'll usually find what you need there.

[@celebutante]

My dad built an AR-15 (and other stuff) when I was a little kid. He used to call them "grief kits." :P

[@dripmaster.g]

Good Job! Don't beat yourself up... we've all been there overlooking the simple things while troubleshooting electronics. Hey, look at it this way... at one moment you probably wanted to throw it off the bench, but now its up and running!

[@woopimagpie]

Geez, I made pretty much this exact same mistake with a NAD 1020 preamp. Intermittent crackle in one channel, pulled the thing to pieces and lost an afternoon trying to figure it out. Just like yours it was a dirty balance pot. And also like you I was mostly glad I didn't break anything and it was an easy fix in the end. That preamp was connected to a pair of NAD 2140 power amps, with an active crossover built from a kit and a pair of hand built transmission line speakers. That system was TASTY. I liked it so much it inspired me to build a similar setup, which I've now done. The only problem is if you turn the volume knob past 3 it's too loud to stand in the room, lol. Those 2140 amps have some proper power and the TLs are VERY efficient. NAD specs on those amps are 120 watts per channel (or 240 watts bridged), but as we know NAD notoriously underrated their amp outputs in the early days when these amps were built. I strongly suspect they're closer to 150 watts per channel.

[@chrishoffman6537]

If I’m not mistaken, product’s labeled Heath were built in the factory. Heathkit products were sold in kit form.

[@kennethrossfeld5532]

My Heathkit AA-1800 power amp came with a small meter to adjust bias - offset

[@smwsmwsmw]

Lots of Heathkits came with meters. In the mid 70s I helped my Dad build a 25" TV; it came with a (relatively simple) multimeter in its own case that was the first thing you had to assemble before you started on the actual TV. After that we did a stereo receiver that had you use the tuning meter as a meter (IIRC there was a switch inside that switched between tuning and measuring).

[@TrevorsBench]

Those look like Heath branded Harman Kardons. Edit; Yeah, have a look at the HK825 and HK870 from Harman Kardon Very good performing gear. Good specs and these should sound great

[@James-dt7ky]

My Sansui AU-717 is working perfectly now. Someone had already made little access holes in the volume pots.

[@RTBNL]

Exactly what came up in my mind. Harman Kardon all over. I’m still in the first minutes but expect the switches to play up. TK and or ELNA caps. The TK’s can be fine but can also be very hard on their way out.

[@TrevorsBench]

I posted before I watched, A YT no-no. lol I did a vid on the HK870. Be sure to check the solder joints on the power transistors. They crack from thermal cycling and can destroy yer speakers.

[@TrevorsBench]

@@James-dt7ky Somebody beat you to it! Good to know

[@RTBNL]

Regarding the resistors deep under the heatsinks. Hirschmann Kleps (2600 or 3000) will do the trick. The bad connection you noticed is caused by oxidation. A little bit of brushing with a fiberglass brush will fix that for a while.

[@yambo59]

Hey I LOVE your favorite song good for judging basic audio performance, great happy little jazz ditty, keep it-!!

[@Jake-tw8qr]

I wish i could get my techs to be this hard on themselves when THEY make mistakes.

[@stephenmorton8017]

I'd like to mention two small things about this. That static you're hearing could just be capacitor reforming that will take a bit of time to settle down depending how long those two units have been disused. It may just go away on its own. Also you might want to use your voltmeter to check the open circuit voltage of the power amplifier before you hook up the speakers on an unknown unit. It's a very simple initial check that can save your your speakers if there's problem with the final output transistors.

[@markrichards3747]

“Put first things first and second things are thrown in. Put second things first and you lose both first and second things.” - C. S. Lewis

[@danb.9891]

Love the LP seat booster. Vinyl fan heads are exploding right now..😆👍

[@MrDoneboy]

We kave to fail, before we can learn. Keep that thought in mind, Aiden. Happy New Year!

[@scorsagain]

I built a Dynaco Dynakit preamp (DYNACO PAT-4} and power amp {Dynaco 120A) in 1970 that blasted away till 1983 when it just gave up. It was great until surround sound (5.1) was the thing to have. I remember that the inductors were made by wrapping so many winds of wire around the large capacitors. Great fun to build. The power amp would also dim the lights when it came on, along with a transformer "bong" until it stabilized.

[@BobBasshead]

I built those and the FM5 mid 70's and still them today, and they work. Had to re-cap the power amp.

[@mdzacharias]

That preamp is definitely a Harman Kardon Inside. The amp, also. I've worked on the HK versions. There was a bunch of deteriorated brown glue on the underside of the main board on the amp.

[@mikecampbell5856]

As soon as you showed the back panel I thought Harman Kardon just like some of the other viewers did. Looks so much like my PM-650.

[@mranalogman3525]

Agree 100% This appears to be a Harmak Kardon HK 825 and an HK 870!

[@THOMMGB]

Aiden, Thank you so much for this video. Don’t be so hard on yourself. You helped a lot of your viewers, including me. I will always try to remember to clean the controls before troubleshooting my equipment, so something good did come out of your oversight. Thanks for showing the idle current adjustment and DC balance adjustment . I need to learn more about this. I hope your Christmas went well with family, friends and good food. And I hope 2025 is even better. - Thomas

[@SleepingLionsProductions]

Its so crazy how much a dirty potentiometer can really just mess things up. I have a Power Amp from RadioShack where the VU meter isnt working, but im very sure its just a dirty trim pot that im too lazy to do anything about

[@maigat]

everyone's favorite song is the perfect mascot for an audio whyfi channel...

[@PossibleAudio]

@16:20.... I've done the same here. I call it chasing our own tail. Nice piece of equipment. Thanks for sharing.

[@terrym1065]

Hoping you and your family had a great Christmas and will have a fantastic New Year. Unique items there, H-K's in disguise and with 130w I'd say pretty healthy. Dirty controls, who'd of thunk that? 😉 Nice job, thanks for the work. See ya soon.

[@KirthGersen-qz9ij]

I built an Heathkit AA-1800 decades ago, and that kit included a meter kit for adjusting biases. I suspect that the meter you found in the power amp was for the same purpose, which makes me suspect that your power amp may have been an actual kit.

[@Poppinwheeeeellllllieeeeez]

Who wants to work on a filthy unit? Clean the outside, clean the controls and test. Enjoy the music while detailing and the ultrasonic is busting grime off the knobs and button caps. That Novus 2 does a great job rejuvenating the shine....that or mothers mag polish.

[@TheOzthewiz]

I wish you could get hold of REALLY vintage Heathkit products, such as the "AR-15" receiver from the late '60s. That unit was TOTALLY created by Heath engineers not a "knocked down" version of some other manufacturers product. The AR-15 went for $600 in 1969($5100 in today's dollars) and cost as much as the "crown jewel" of audio back then, the Marantz Model 10 tuner. Heathkit had some "cutting edge" stuff back then, such as the "GR-93" 21" COLOR TV KIT! I purchased one in 1964, took me about a week to "assemble" and do the "color" setup. It was one of the "early" designs with the 90* CRT. Had a FANTASTIC image, but ONLY in a TOTALLY dark room because of the early "sulfide phosphor" CRT. The kit used RCA pre-built tuner, IF strip and HV section. Everything else was in "through hole" kit form, NO "SMT" back then! Those were FUN times!!

[@Mrsteve4761]

Everybody's favorite song (and mine) has become your signature and should never be changed! Good for you to inform the rest of us who, and for some, could easily have fallen prey to the same situation. Nice job in the end.

[@JuanGarcia-kv7yv]

Looking forward to seeing the video on that Carver !! Great little units with tons of clean power but after 30 years or so, it’s bound to need some service.. The cat sure has her priorities in order!!l. 😂

[@frankgeeraerts6243]

You're not alone with this kind of experience.............

[@Mark-qw8lc]

Regardless of the controls cleaning this was a fun and interesting video. Thank you!

[@Daltondoubledeuce]

Merry Christmas 🎄! Love these vids :)

[@kbklt1]

Thank you! I needed company on this bus. I do this or something like it a lot!

[@andrew1977au]

I've got a Marantz, HK and monarch Amps and split my signal to all 3 and use a speaker switcher so there is very minimal delay between switching between Amps, with my mirage M3si speakers, my HK sounds the best out of all the Amps. Great video, I caught on right away it was the same as a HK and when I got mine I had the balance issue, lucky for me I went and fixed that first.

[@0MyWay01]

The amplifier was a kit with an extra part and the owner stuck it inside thinking they would figure it out later.

[@ripjones5294]

Nope. It was used to set voltages during final assembly of the kit.

[@blipco5]

Add a Marantz tuner to your new setup. 👍

[@pietromanno8916]

HAPPY HOLIDAYS!! GOOD JOB!!!!! ✨✌️⚡✨

[@Jammerk40]

Merry Christmas Mr. Fix It and wishing you a Happy New Year!

[@Sunnbobb]

I've come to love my Phase Linear 400 (modified with White Oak Audio upgrade and Watts abundant Speaker Relay) with my Planar speakers. Lots of clean a/b power is the ticket.

[@thomaskendall452]

Hee hee! Always clean the controls first, even if they seem okay! Merry Christmas and Happy New Year to you and yours!

[@vincentrockel1149]

I was wondering if you had cleaned the pots.. Figured that was the first step..

[@hoaxs1939]

A great takeaway is now you what a dirty balance control looks like on the scope.

[@stephenmorrissey1254]

Thank You Thank You for keeping in the mistakes. That's how we all learn.

[@rodgerwilliamson2777]

Meter, possibly supplied for adjusting the Bias???

[@Roscoeverdin5469]

It used to be my favorite song until I found another KZbinr using it too.

[@d0wnboy]

It’s about 1986. I’m at a customer site working on a 600MB CDC disk drive that’s failed (it’s the size of a big file cabinet), I have a scope hooked to this thing, running diags, and CANNOT get it to work. I’ve been up all night. Call one of my colleagues in to take a look and he discovers I didn’t put one of the 20 boards back in the card cage as I was swapping spares in and out. Put the board back in and about an hour later after replacing another board we’re up and running. We’ve all been there.

[@seankearney2592]

Your correct it is everyone favourite song....i love it...

[@marktubeie07]

I'd like to add that it's my favourite song too - but only on this channel _(& Dankpods channel as well) !!_

[@grooveduststudio]

Mark Twain “History doesn't repeat itself, but it often rhymes”.

[@louoldschool7047]

i love the song, and cold showers, and warm beer, and rainy days

[@dont-want-no-wrench]

those advents are real nice, i have a pair daily use

[@tiojimmy3425]

I have those Advents in my camper 😅 and Double Advents (large) in my bedroom as the number twos😊... Great sound to this day👍!!

[@detroitboy65]

I rember a Heath Kit store (crazy warehouse more like) near my house in the 70s and 80s. I practically lived there! Rig centers rule!

[@timmooney7528]

There used to be a Heath store near me. It was located on the back side of Heath's plant in St Joseph, Michigan. The store was selling computers and educational products. The store apparently was making profit, however they were selling more Apple products than ZDS systems. ZDS shut the store down because it was supposed to be a retail outlet for ZDS computers, and selling Apples became a conflict of interest.

[@peterlundskow4061]

Looking forward to you looking into the Carver!

[@grahamluscombememories9897]

I thought it was recommended to turn off the power when connecting and disconnecting inputs and outputs? BTW, it is really great to see someone admit when they have made a mistake. This is how we all learn and I really appreciate your honesty!

[@h0ll0wm9n]

Thumb's way up for honesty!

[@martyh9309]

Agree! It is everyone's favorite song!!

[@australianbloke3934]

Ha ha. Except that it is not a song. A song, by definition has to be sung. I hear no singing. 🙂

[@leamanc]

Don’t beat yourself up! The more we know, the more we think it’s got to be something complicated. That said, I always try to remind myself to check the simple stuff first😅

[@dogpdsound]

Great video. Thanks, I'm looking forward to more new ones in 2025

[@dperreno]

Hey, live and learn! We have all done something similar. It's actually very rare for us to internalize something like this the first time. It usually takes a few misfires to learn and remember.

[@pauldavis6356]

You found your error and remedied it. At least you didn't order and install a bunch of new components for it before you did.

[@Silent-Lucidity]

I listen to our favorite song, 24/7!!

[@b.powell3480]

It's the u-tube favorite fault song !!!

[@billmcdonald4335]

TrackTribe released a full hour version of the best song ever written. Isn't that great?

[@TheShitTzu]

this is harman kardon cictation selled under other brand. i had it couple of times. repaired

[@manosmul6827]

Great video :) I mostly come here to listen to my favourite song. All the best.

[@babalooey100]

The kit had all the components soldered in - at least for the aa-2500

[@b.powell3480]

Well, at least you didn't disassemble the whole unit with parts all over bench, only to find you had it unplugged!!!!

[@JohnChrysostom101]

Healthkit started making a few kits again it's not a huge selection but it's something

[@branhicks]

Don't ruin the Advents! I have some throwaway speakers for stuff like this ever since an old Amp put 40 volts out directly to the speaker terminal and blew them. Also, it seems strange that the preamp would have a protection circuit.

[@Mrsteve4761]

It's likely a muting circuit to suppress turn-on/turn-off/input-switching transients that would be amplified downstream. My Apt Holman preamp works in this way.

[@aegisofhonor]

the fact you could still buy a KIT to build the amp yourself is crazy, that was common back in the 1950s and 60s but even by the early 70s "stereo kits" were becoming very rare and pretty much never an option for Japanese made gear. Heath was probably last major company to have kits as an option.

[@scrappy7571]

Hafler still had kits, not sure when those were stopped.

[@BCov]

Appreciate you actually sharing the mistakes so we all learn from them. Suggestion: create a checklist so you ensure you follow the same initial diagnostic process each time and don't miss/forget the simple things, then you can share with all of us as well.

[@glenwhatley4125]

An audio signal tracer would find that problem more effectively.

[@reinkansman1081]

Ironic that this is the newest piece you have worked on and it is still older than you. BTW, still my favorite tune. Stay true

[@thewheelman282]

awesome video! please go back into the power amp and fix the solder joints on those wires. that thing was definitely hobbyist assembled, and those joints are not making a good mechanical connection.

[@FredCDobbs151]

I'll bet that amp is a home built unit and that little meter was used to set the bias or DC offset??? Just a guess.

[@jpvoodoo5522]

I do the same stuff with PCs. An hour deep into network configuration to find out the printer is off.

[@martyh9309]

Power amp was definitely a kit build.

[@salvatoreoddo-x9t]

I have a marantz 2226b that I bought from a thrift store for 20$ and a pair of Polk model 7b for 5$ for the pair. The combination sounds amazing! Cant believe the bass that it can make. There is a song on Laurie Andersons "Mr Heartbreak"that has a 4 note bass line that sounds great.

[@davidodonoghue3450]

Always had the same bench speakers, Smaller Advent.

[@historymakesmesleep]

WOW Heathkit my dad built a color tv when i was a kid

[@robertdavis5714]

Jazz Fan...........................So I enjoy your "Walk in the Park" Have made same mistake with dirty/oxidized Pot controls and switches as well.

[@OctopusHandler]

A Japanese made piece with Heathkit's name on it. Made by Pioneer?

[@777gordini]

Chaps comment above at top is correct..Harmon Kardon..

[@geminijinxies7258]

One day you should hook up with the musicians responsible for our favorite song. The essential classic "Walk in the Park" by Jazz Instrumental Relax Center!!

[@ThorstenBude999]

Look at the backside of this amp... check the transistors under the covers . Thermalpaste is most of the problems and often the solder joint cracked. Watch it on trevors bench.. set is the same as Harman Kardon hk870. helps me a lot. But good job. This set sounds impressive. Greetings from germany

[@dont-want-no-wrench]

that is a nice set, wish i had one.

[@ingenfestbrems]

9:25 Tektronic and fluke fancy 😁

[@davidodonoghue3450]

The first thing you should have done is see if the noise was at the tape output.

[@mikepxg6406]

It's called a "Learning Curve Tracer".

[@psychrocklive]

My current mains are Maggie MMGs and I can attest to your information. I have them running on a 120WPC yamaha integrated with DAC. It sounds super detailed and the soundstage is huge. For my money, the maggies love big modern power. Fun to play with, maybe tube pre and modern power amp?

[@andrewcastellane7802]

use the O-scope to trace the signal, dont get flustered and confused because the Volt readings dont exactly match the schematic, they rarely do.

[@ericbachmann8037]

The Heat sinks in the power amp look very similar to Proton amp heat sinks

[@battbatt17]

Touch by Daft Punk @17:54 is the perfect test song.

[@intothevoid9831]

Those look like rebranded Harman Kardon 825/870 power and preamp combo

[@ThorstenBude999]

it s the same

[@spacemissing]

I was thinking HK as soon as I saw the units. They should sound Really good once fully serviced.

[@StefanBodin]

What kind of dummy load for stereo amplifiers do you use.

[@barryg.291]

When i saw the Heath units i was struck by how similar they both looked to my Adcom units of the early 90's. Same pre-amp/power amp specs at 100w per side. I was always impressed by the Adcom power and sound staging. The faces are almost identical. Adcom used round buttons where the Heath used square buttons. Other than that, identical as i remember them. Do you think the manufacturers purchased generic face plates from suppliers. I had opened my components several times and do not remember the "rods" extending back to adjustable pots. Do you have any thoughts on this?

[@Mate2Frio]

So those two were sold new for $2,273 in today's money.

[@MrMatslars]

It's a great favourite song