Hey this is my first post in the Solid State forum. Recently i've had the opportunity to purchase a HK 630 from a friend of my for $40. Apparently it doesn't work because of a blown fuse but was working 1 year ago. Cosmetically the amp looks very nice. I've looked around for information on this particular amp and can't find much information other than an owners manual. Currently I have a Yahama HTR 5730 as my receiver and it is a cheap $200 one. I'm curious if this HK 630 will outperform my yamaha receiver. Also besides the fuses, will this amp possibly require capacitor replacements?
Any general information on this amp is much appreciated.
Thank You.
Any general information on this amp is much appreciated.
Thank You.
Yea I looked at the service manual from Harman's site. Thanks for the link Latala. The dual power supplies feature certainly looks interesting, but it still only develops 30w/channel at 0.5% distortion. Wouldn't the expected power be higher? Does this amp run in class A? I don't see why it needs the dual power supplies.
Hi angsuman,
It runs hot, but not in class "A". The dual transformers were (and still are) all the rage back then.
Sound quality does not get better with power necessarily. There are several small amplifiers from England in this power class.
A percentage figure does not completely tell the whole story. Listen to it. If you don't like it, don't buy it.
-Chris
It runs hot, but not in class "A". The dual transformers were (and still are) all the rage back then.
Sound quality does not get better with power necessarily. There are several small amplifiers from England in this power class.
A percentage figure does not completely tell the whole story. Listen to it. If you don't like it, don't buy it.
-Chris
Well said Chris
Coming clean now i was involved for a period of 25 years in hifi retail and sold / serviced most of what was availabe in the UK.
Harman Kardan is without a doubt one of the best world class products ever made. quality of build etc.
I have left the audio industry now (well i got used to eating ) and went out in to the Chemical industry where the money to be made was in the order of magnitudes greater.
But since i have collected about 10 HK every one worked all from E-bay its great stuff!
You can not tell from figures alone how good /bad a piece of audio is you have to try it!
and if it works after 30/40 years it must be good
regards Trev
Ps the 630 is a simple amp tht is synergeticaly designed its sound is much better than can be expected from the scematic alone!!!
Coming clean now i was involved for a period of 25 years in hifi retail and sold / serviced most of what was availabe in the UK.
Harman Kardan is without a doubt one of the best world class products ever made. quality of build etc.
I have left the audio industry now (well i got used to eating ) and went out in to the Chemical industry where the money to be made was in the order of magnitudes greater.
But since i have collected about 10 HK every one worked all from E-bay its great stuff!
You can not tell from figures alone how good /bad a piece of audio is you have to try it!
and if it works after 30/40 years it must be good
regards Trev
Ps the 630 is a simple amp tht is synergeticaly designed its sound is much better than can be expected from the scematic alone!!!
this being DiyAudio after all! Can you think of a better chassis?Well it certainley would be a looker ! with a built in tuner
And would bring the unit onto this century! Allthough if there are any real problems with the Hk it would be the rather primitive preamp
However i think he will find very little wronge with it !
I must admitt that i have wondered how an older circuit such as the HK would perform with modern devices as the outputs etc would have been derrved from the old 2n3055 family etc in fact the Hk power amp seems to be derrived from an early RCA application note
My amp collection is vast I must have over a hundred or so units Quads Sugdens Radford Armstong Amcron Bgw Phase linear etc but I just love the HK sound
regards Trev
And would bring the unit onto this century! Allthough if there are any real problems with the Hk it would be the rather primitive preamp
However i think he will find very little wronge with it !
I must admitt that i have wondered how an older circuit such as the HK would perform with modern devices as the outputs etc would have been derrved from the old 2n3055 family etc in fact the Hk power amp seems to be derrived from an early RCA application note
My amp collection is vast I must have over a hundred or so units Quads Sugdens Radford Armstong Amcron Bgw Phase linear etc but I just love the HK sound
regards Trev
Well you are right there They can normally be picked up for about thirty pounds! British
So it would not be a great Loss !
As I don,t drink, smoke and have been married for 30 Years so SEX is out. I suppose I must do something to keep me happy
Yes i will do it !!! however I must finnish This Musical Fidelity Synthesis or My best mate will never talk to me again but to be honest I have been sitting on it for 2-3 years without looking at it
regards Trev
So it would not be a great Loss !
As I don,t drink, smoke and have been married for 30 Years so SEX is out. I suppose I must do something to keep me happy
Yes i will do it !!! however I must finnish This Musical Fidelity Synthesis or My best mate will never talk to me again but to be honest I have been sitting on it for 2-3 years without looking at it
regards Trev
I have obtained a HK 630 from E-bay fo £18 british pounds ( thats value) as a donor for my latest project ! Now then Anatech when you say do it !Did you mean just upgrade to the latest devices with the origional circuit and then measure the differance in performance!
Or are you suggesting a new power amp?
My first inclination is to first just upgrade the devices !
regards Trev
Or are you suggesting a new power amp?
My first inclination is to first just upgrade the devices !
regards Trev
I have already made the comparison with Symassym
The HK630 circuit was assembled and compared.
Symassym win in bass extension, also in dinamics, had almost the same voices with sligth advantage to Symassym 4, and the model 4 lost in hi frequency extension and quality to high end.
Symassym 5 was listened but not compared....i think it will win the Harman... and with a very good advantage...but...i did not made the comparison of this unit with the Sym 5.
The HK distorted diferent, very nice, and produced more brigth in the trebles....this was perceived, my subjective point of view, in A to B comparison made monthes ago.
Comparing those two amplifiers..i think you will decide to keep both near you.
I made the comparison last January, and i have used the same transistors used in Symassym....as i use to do, not to be fooled by different transistors.
The Amplifier was dismounted because the parts, but really i am thinking to construct it once again....also the 430 sound very good, and with more details...even better, despite older.
Now i am thinking in the 670....i think i will assemble the baby monster.....80 watts over 8 ohms with a very small distortion and the dinamic headroom easy goes to 120 watts rms.
The Harman Kardon is a hell good unit, and Symassym is hardly guaranteed.
regards,
Carlos
The HK630 circuit was assembled and compared.
Symassym win in bass extension, also in dinamics, had almost the same voices with sligth advantage to Symassym 4, and the model 4 lost in hi frequency extension and quality to high end.
Symassym 5 was listened but not compared....i think it will win the Harman... and with a very good advantage...but...i did not made the comparison of this unit with the Sym 5.
The HK distorted diferent, very nice, and produced more brigth in the trebles....this was perceived, my subjective point of view, in A to B comparison made monthes ago.
Comparing those two amplifiers..i think you will decide to keep both near you.
I made the comparison last January, and i have used the same transistors used in Symassym....as i use to do, not to be fooled by different transistors.
The Amplifier was dismounted because the parts, but really i am thinking to construct it once again....also the 430 sound very good, and with more details...even better, despite older.
Now i am thinking in the 670....i think i will assemble the baby monster.....80 watts over 8 ohms with a very small distortion and the dinamic headroom easy goes to 120 watts rms.
The Harman Kardon is a hell good unit, and Symassym is hardly guaranteed.
regards,
Carlos
Attachments
I also love those old Harman, also some Yamaha models and Nad units
There are very good units in the comercial line...from 1980 to 1990.
I am feeling passion for this one..... very similar....topologie is the same as HK670..... a more modern amplifier.....near the new century, this time we are living.
regards,
Carlos
There are very good units in the comercial line...from 1980 to 1990.
I am feeling passion for this one..... very similar....topologie is the same as HK670..... a more modern amplifier.....near the new century, this time we are living.
regards,
Carlos
Attachments
Thank You Carlos
For coming in on this discussion
When you built you HK 630 circuit did you use new type transistors? If so what devices did you use ?
All my Knowledge is now dated as I have only come back to audio after being out of the game for the last twenty years !
This was because life happens and I did not have the time.
I am lucky enough to have a great many amplifiers but nothing has ever thrilled me like the sound of self made equipment. I have a self design of class A with sliding bias that I developed years ago which is better than my quads/sugdens and radfords etc that I may but on the site all though I am a little nervouse to offer my wares to such an esttemed audience.
As far as I am concerned there is no best solution just as there is no best music!
Its all a matter of taste!
Regards Trevor
For coming in on this discussion
When you built you HK 630 circuit did you use new type transistors? If so what devices did you use ?
All my Knowledge is now dated as I have only come back to audio after being out of the game for the last twenty years !
This was because life happens and I did not have the time.
I am lucky enough to have a great many amplifiers but nothing has ever thrilled me like the sound of self made equipment. I have a self design of class A with sliding bias that I developed years ago which is better than my quads/sugdens and radfords etc that I may but on the site all though I am a little nervouse to offer my wares to such an esttemed audience.
As far as I am concerned there is no best solution just as there is no best music!
Its all a matter of taste!
Regards Trevor
Trevor, please, publish or send me your sliding bias circuit
I will be happy to see your design...i think everybody will apreciate.
I have used in this schematic:
2N5401 for differential...gain 120...from Fairchild
2SC1819 for voltage amplifier, gain 70, from Mitsubishi or Matsushita...not sure...the three diamonds painted.
BD139 was used for voltage amplifier, gain 100, from Philips
2SC4793 and 2SA1837, drivers from Fairchild, gain was 80
2SC5200, big output from Toshiba was used ...gain 90
Driver`s capacitors were removed.
Voltage amplifier capacitor reduced to 22pf, silver mica
The series diode, in the positive rail, received a switch to by pass the unit....so...it was tested with diode working and diode bypassed....i suggest you to keep the diode.
Good to know you are an old fellow as i am...welcome to the daily pain club...today my bonds were producing me pains.... what about you?
regards,
Carlos
I will be happy to see your design...i think everybody will apreciate.
I have used in this schematic:
2N5401 for differential...gain 120...from Fairchild
2SC1819 for voltage amplifier, gain 70, from Mitsubishi or Matsushita...not sure...the three diamonds painted.
BD139 was used for voltage amplifier, gain 100, from Philips
2SC4793 and 2SA1837, drivers from Fairchild, gain was 80
2SC5200, big output from Toshiba was used ...gain 90
Driver`s capacitors were removed.
Voltage amplifier capacitor reduced to 22pf, silver mica
The series diode, in the positive rail, received a switch to by pass the unit....so...it was tested with diode working and diode bypassed....i suggest you to keep the diode.
Good to know you are an old fellow as i am...welcome to the daily pain club...today my bonds were producing me pains.... what about you?
regards,
Carlos
Thanks Carlos
While we are talking about the capacitor on the driver being reduced to 22pf Have you ever tryied to take that capacitor and connect it from the collector of the driver transistor to the base of the feedback leg of the differential input stage this is some thing I nearly always do As I find that this improves the performance with regards to" TID" Transient Intermodulation Distortion!
I picked this up years ago from where? I can not remmember
It is wonderfull to be able to discuss these ideas at last
regards Trev
While we are talking about the capacitor on the driver being reduced to 22pf Have you ever tryied to take that capacitor and connect it from the collector of the driver transistor to the base of the feedback leg of the differential input stage this is some thing I nearly always do As I find that this improves the performance with regards to" TID" Transient Intermodulation Distortion!
I picked this up years ago from where? I can not remmember
It is wonderfull to be able to discuss these ideas at last
regards Trev
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