What New Stuff Have You Bought? If You Care To Share Thead! :)

[zieglj01]

I also picked up some budget HK for $19 -- however, I do not know if they are Harman or a company called Hong Kong Audio.

 

[lovinthehd]

@zieglj01 just how many speakers do you have??

 

[j_garcia]

I also picked up some budget HK for $19 -- however, I do not know if they are Harman or a company called Hong Kong Audio.

Their official logo is harman/kardon all the way back to the 70s, so I kind of feel like those are Hong Kong something-or-other lol.

 

[zieglj01]

@zieglj01 just how many speakers do you have??

I have owned over 90 sets -- 87 are no longer with me.

 

[zieglj01]

Their official logo is harman/kardon all the way back to the 70s, so I kind of feel like those are Hong Kong something-or-other lol.

If they do not have that JBL or Infinity flavor -- then I will know. Maybe I can mod them, if I can get that grill off.

 

[j_garcia]

If they do not have that JBL or Infinity flavor -- then I will know. Maybe I can mod them, if I can get that grill off.

That little hump in the front is odd.

 

[zieglj01]

That little hump in the front is odd.

Yes it is. And there is a company called Hong Kong Audio
http://hkaudio.com/products.php?sid=35

 

[zieglj01]

Their official logo is harman/kardon all the way back to the 70s, so I kind of feel like those are Hong Kong something-or-other lol.

Sometimes you get a pleasant surprise -- these are Harman Kardon to me. They arrived today and they pass the door knock test. The woofer looks to be the same as the one in the Harman Kardon Ten. These could very well be the former series.

They have some good wood, it was hard to take the screws out of the terminal cup and woofer -- but the terminal cup and woofer still did not come out. It was a pain to put the screws back in. Shinning a flashlight in the port revealed carpet felt padding inside. The same padding that is inside the 10's that should arrive tomorrow.

The spring type terminals do accept bananna plugs. The sound is robust and some what lively. The sound is slightly forward, yet engaging. The imaging and sound-stage is good. The hard dome tweeter is not harsh or annoying. Their sound and performace is above entry level mass market.

Take Five from Dave Brubeck sounds good.

 

[rojo]

Sometimes you get a pleasant surprise -- these are Harman Kardon to me. They arrived today and they pass the door knock test. The woofer looks to be the same as the one in the Harman Kardon Ten. These could very well be the former series.

They have some good wood, it was hard to take the screws out of the terminal cup and woofer -- but the terminal cup and woofer still did not come out. It was a pain to put the screws back in. Shinning a flashlight in the port revealed carpet felt padding inside. The same padding that is inside the 10's that should arrive tomorrow.

The spring type terminals do accept bananna plugs. The sound is robust and some what lively. The sound is slightly forward, yet engaging. The imaging and sound-stage is good. The hard dome tweeter is not harsh or annoying. Their sound and performace is above entry level mass market.

Take Five from Dave Brubeck sounds good.

+1 just for "Take Five" from Dave Brubeck

 

[zieglj01]

+1 just for "Take Five" from Dave Brubeck

A good way to test any speaker.

 

[j_garcia]

The SACD of Time Out is one of my favorite discs.

https://www.amazon.com/Time-Out-Dave-Brubeck/dp/B00ZWN148W/ref=sr_1_1?ie=UTF8&qid=1488928929&sr=8-1&keywords=time+out+sacd

 

[MrBoat]

I just bought one of those cheap amplifier boards to mess around with.
http://www.parts-express.com/sure-electronics-aa-ab32189-2x100w-tda7498-class-d-amplifier-board--320-303#!

And a meager power supply.
http://www.parts-express.com/mean-well-mw-nes-200-24-24-vdc-88a-200w-regulated-switching-power-supply--320-3140

It's probably junk. Will see if it is something I am interested in on the cheap, first.

 

[slipperybidness]

I just bought one of those cheap amplifier boards to mess around with.
http://www.parts-express.com/sure-electronics-aa-ab32189-2x100w-tda7498-class-d-amplifier-board--320-303#!

And a meager power supply.
http://www.parts-express.com/mean-well-mw-nes-200-24-24-vdc-88a-200w-regulated-switching-power-supply--320-3140

It's probably junk. Will see if it is something I am interested in on the cheap, first.

I've been looking at those PE boards for a while now. Very interested to know your impressions. Those look like they would work well for integrated project amplification, maybe even for building some active/powered speakers too.

One note--I am not a fan of SMPS, especially where audio is concerned. In my opinion (without having any experience on these boards yet), moving to a linear PS would probably be my first upgrade here.

SMPS just isn't ideal for audio for many technical reasons. They are getting to be fairly common for audio, and they are getting better in general. But, there is a lot of complexity to engineer-out the inherent problems with these SMPS devices, and that makes them less reliable.

I'm giving you the sugar-coated version, ask TLS his thought on SMPS

Anyway, a Class D amp circuit topology indeed has more in common with SMPS than it does with a classic class A or AB amp topology. So, SMPS + Class D amp does make some sense.

And, a note on the fan--I prefer passive cooling, nothing to fail with that approach. But, it is larger and more expensive than forced-air cooling.

Probably more info than you wanted

 

[zieglj01]

Sometimes you get a pleasant surprise -- these are Harman Kardon to me.

They have some good wood, it was hard to take the screws out of the terminal cup and woofer -- but the terminal cup and woofer still did not come out.

Well, I finally got the terminal cup out to look at the crossover - and the size of the wood. It is 1st order, same crossover type as the origional PSB Alpha and Cambridge 30. The HK cabinet is thicker than the other two -- the HK cabinet is 3/4 inch thick. Name on Crossover is HK-1SL

 

[MrBoat]

I've been looking at those PE boards for a while now. Very interested to know your impressions. Those look like they would work well for integrated project amplification, maybe even for building some active/powered speakers too.

One note--I am not a fan of SMPS, especially where audio is concerned. In my opinion (without having any experience on these boards yet), moving to a linear PS would probably be my first upgrade here.

SMPS just isn't ideal for audio for many technical reasons. They are getting to be fairly common for audio, and they are getting better in general. But, there is a lot of complexity to engineer-out the inherent problems with these SMPS devices, and that makes them less reliable.

I'm giving you the sugar-coated version, ask TLS his thought on SMPS

Anyway, a Class D amp circuit topology indeed has more in common with SMPS than it does with a classic class A or AB amp topology. So, SMPS + Class D amp does make some sense.

And, a note on the fan--I prefer passive cooling, nothing to fail with that approach. But, it is larger and more expensive than forced-air cooling.

Probably more info than you wanted

Hey, you started this DIY amp thing. Not that 'this' is 'that', but it got me looking. Then I spent an evening last night reading about the "Gainclone," and other entry level stuff. Then I discovered that one of the favored parts (LM3875 opamp) for it is obsolete. So maybe you can tell me your take on this simple amp, or I can start a thread in the DIY section about it this evening when I get home.

I also thought that the PS would be wrong, but I am treating this like a novelty toy from Radio Shack and really didn't expect much more than that.

ETA: The power supply reminds me of the ones used in a desktop pc tower except with 24v instead of 12. I didn't do a lot of research in this area yet. I probably already have decent transformers right under my nose in old amps and stuff that I have around here.

Also, I don't mind the fan. I thought it made it look cool.

Thank you for replying.

 

[zieglj01]

Off Ebay -- Harman Kardon Ten bookshelf speakers -- use to sell for around $350 to $375 a pair in the 90s -- seller listed them for $59 -- He excepted my offer of $40 -- I bought a pair in the past from Circuit City when they were being discontinued.

Well, my Harman Kardon Ten showed up. They are a clear step up above the mystery HK speakers. The pair I got from Ebay are in real good shape. The woofer has a better voice coil, the tweeter is 3/4 inch soft dome, and they have a second order crossover on both the woofer and tweeter.

Voices are rich and clean with good depth -- they have good sharp imaging with good detail and definition, the soundstage is good both central and wide. Bass is clean and tight and articulate.

The speakers have piano gloss on the sides, cloth covering on top and bottom, and for the 90's like JBL -- the banana plug terminals are upside down. The tweeter and woofer seems to be sourced from Vifa. They sound much better than I remember.

 

[rojo]

Well, my Harman Kardon Ten showed up. They are a clear step up above the mystery HK speakers. The pair I got from Ebay are in real good shape. The woofer has a better voice coil, the tweeter is 3/4 inch soft dome, and they have a second order crossover on both the woofer and tweeter.

Voices are rich and clean with good depth -- they have good sharp imaging with good detail and definition, the soundstage is good both central and wide. Bass is clean and tight and articulate.

The speakers have piano gloss on the sides, cloth covering on top and bottom, and for the 90's like JBL -- the banana plug terminals are upside down. The tweeter and woofer seems to be sourced from Vifa. They sound much better than I remember.

Hey zieg, thanks for wearing clothes while snapping a picture of the piano finish.

Spoiler: nsfw!

(unlike this guy)

 

[zieglj01]

Hey zieg, thanks for wearing clothes while snapping a picture of the piano finish.

Your welcome.

 

[slipperybidness]

Hey, you started this DIY amp thing. Not that 'this' is 'that', but it got me looking. Then I spent an evening last night reading about the "Gainclone," and other entry level stuff. Then I discovered that one of the favored parts (LM3875 opamp) for it is obsolete. So maybe you can tell me your take on this simple amp, or I can start a thread in the DIY section about it this evening when I get home.

I also thought that the PS would be wrong, but I am treating this like a novelty toy from Radio Shack and really didn't expect much more than that.

ETA: The power supply reminds me of the ones used in a desktop pc tower except with 24v instead of 12. I didn't do a lot of research in this area yet. I probably already have decent transformers right under my nose in old amps and stuff that I have around here.

Also, I don't mind the fan. I thought it made it look cool.

Thank you for replying.

Yeah, the GainCARD is what started the ChipAmp niche, and now there are many Gainclones on the market. My DIY designs so far have basically been Gainclones, I haven't done a full discrete amp yet, I've kind of moved along to other hobbies for a while, I'll get back to amp building eventually. When I do, I would like to do my own PCB etching too!

Actually, the LM3875 is a POWER AMP, not an OPAMP. I can't remember the distinction off the top of my head, but once a chip handles a certain power (Watts), then it's called a "PowerAmp". But, if the LM3875 isn't available, it's a moot point b/c it has been superseded by the LM3886, and this is the chip that I have been using most.

Honestly, as long as you don't need huge power requirements, the Gainclone is a heck of an amp! Likely would work great on those Tempests.

I have this kit that is a Gainclone, built it and measured it for my Solid State class a few years ago. Odd, but now it shows as discontinued. I caught it on sale for $120 delivered, and very tough to beat at that price, now it's showing as $185 and not in stock, likely better options at that price anyway. Furthermore, when I bought my kit the guy offered me a free headphone amp kit if I would post my review and measurements on his site! Score! So, I also have one of his CMOY headphone amp kits (he doesn't call it CMOY, but that's what it is, just like he doesn't call his amp a gainclone but that's what it is).

https://www.boxedkitamps.com/gobo-stereo-audio-amp-kit

And, I think this guy may be top dog as far as chip amps (gainclones) are concerned:
https://www.neurochrome.com/modulus-86-rev-2-1/

The PS isn't "wrong", and it's actually pretty common to use it for those type amp boards. It's just that there are "better" out there for this application. You may see it in a PC, but it's very common in other electronics gear, for example my 3D printer has that same style PS.

Yeah, if you treat this amp like a "radio shack novelty", then you won't be disappointed. But, I really suspect that you are going to be pleasantly surprised by this amp (even though I don't have experience with it). Here's the thing, amps aren't some magic device, the technology has been well understood for a very long time. Furthermore, you are discovering for yourself, you really don't have to spend a lot of $ to get killer audio!

Amp power supplies aren't too terribly difficult. The preferred topology is a Non-Regulated Linear PS. For the amps that I have built from the ground up, I have started with the PS design as my main goal to really understand and design correctly to fit the application. But, my designs so far have been +/- rails, I'm not certain if this amp just uses a + rail?

 

[MrBoat]

Yeah, the GainCARD is what started the ChipAmp niche, and now there are many Gainclones on the market. My DIY designs so far have basically been Gainclones, I haven't done a full discrete amp yet, I've kind of moved along to other hobbies for a while, I'll get back to amp building eventually. When I do, I would like to do my own PCB etching too!

Actually, the LM3875 is a POWER AMP, not an OPAMP. I can't remember the distinction off the top of my head, but once a chip handles a certain power (Watts), then it's called a "PowerAmp". But, if the LM3875 isn't available, it's a moot point b/c it has been superseded by the LM3886, and this is the chip that I have been using most.

Honestly, as long as you don't need huge power requirements, the Gainclone is a heck of an amp! Likely would work great on those Tempests.

I have this kit that is a Gainclone, built it and measured it for my Solid State class a few years ago. Odd, but now it shows as discontinued. I caught it on sale for $120 delivered, and very tough to beat at that price, now it's showing as $185 and not in stock, likely better options at that price anyway. Furthermore, when I bought my kit the guy offered me a free headphone amp kit if I would post my review and measurements on his site! Score! So, I also have one of his CMOY headphone amp kits (he doesn't call it CMOY, but that's what it is, just like he doesn't call his amp a gainclone but that's what it is).

https://www.boxedkitamps.com/gobo-stereo-audio-amp-kit

And, I think this guy may be top dog as far as chip amps (gainclones) are concerned:
https://www.neurochrome.com/modulus-86-rev-2-1/

The PS isn't "wrong", and it's actually pretty common to use it for those type amp boards. It's just that there are "better" out there for this application. You may see it in a PC, but it's very common in other electronics gear, for example my 3D printer has that same style PS.

Yeah, if you treat this amp like a "radio shack novelty", then you won't be disappointed. But, I really suspect that you are going to be pleasantly surprised by this amp (even though I don't have experience with it). Here's the thing, amps aren't some magic device, the technology has been well understood for a very long time. Furthermore, you are discovering for yourself, you really don't have to spend a lot of $ to get killer audio!

Amp power supplies aren't too terribly difficult. The preferred topology is a Non-Regulated Linear PS. For the amps that I have built from the ground up, I have started with the PS design as my main goal to really understand and design correctly to fit the application. But, my designs so far have been +/- rails, I'm not certain if this amp just uses a + rail?

Good information. The links you posted on my 'build more' thread got me looking. One of the kits they offered said; "Not for beginners." That made me look into the beginner stuff. It was intriguing to read about.

My boss is an electronics engineer for a major manufacturer/contractor. When I told him what I was doing, he gave me a couple LM3875's, a soldering pen, a lighted magnifying lamp, and said to make a list of other components I might need, including transformers, valve parts, LED's, whatever. I guess he used to service his and his friends TV's and such back in the day as well so he has stuff. . . ."laying around."

I have no idea what type of amp the one I bought is, or what exactly "rails" are so your guess is better than mine. I did a little more reading last night on power supplies themselves. I remember a bit how transformers and rectifiers work so I wasn't totally lost other than perhaps the terminology.

Either way, it looks like something I may enjoy doing, at least once or twice. I like the idea of designing my own enclosure. With my welding skills and the materials I have on hand, I could easily make my own heat sinks, which might be kind of unique to this hobby.