Another nice video. Keep 'em coming! One small thing to note is that if you are going to chase a channel imbalance in the tone/preamp stage, make sure your balance is centered. Ask me how I know.
That sounds so much like something I'd do that I'm starting to wonder if we were separated at birth! Seriously, that's a VERY important point. Appreciate you bringing it up!
Thank you for posting this video! I recently picked up an HK 930 that I need to replace the balance control pot as it's broken, i.e. the actual knob is missing. I had to use nose pliers to get to the center. That said, I tested it and noticed that there is definitely an audio imbalance as well. I'll replace the pot first and if it persists, then I will go down the same path you did, so thank you for showing me what to look for next!
@@raygianelli3612 Just replaced the balance pot, and it's working perfectly now!! That said, do you know which caps/transistors are troublesome? I'd love to do a full restoration on this beauty.
@@jpreza Joseph, I only had that one for repair, so I can't say definitively which ones are issues. That said, most of this stuff is getting to the age where a blanket recap makes sense.
@@raygianelli3612 I just did a full recap over the weekend. The most difficult board was the main board behind the display. Pulling out the board for a recap would have required a full dismantling of the unit and I wasn't about to do that. Took me about 6 hours total. Glad it's done!
13:45 I have a DATS V3 interface that I really haven't started playing with yet, and I wasn't aware it has such a detailed capacitor measurement function, so, now I need to explore it more. Thank you for the video, good stuff!
he mentioned this in another video and i thought the same thing. then i promptly forgot about it. now this video reminded me that i need to use dats to measure caps. as soon as i get this 2230 of the bench, i'm gonna measure some known bad and some brand new caps.
@@josephlalock8378 I'm thinking of creating some content on replacing the capacitors on.... my 2 air conditioning compressor units, as both have 15+ year old caps in them ( and I have the new replacements on hand already). I think it will make for an interesting test of the DATS data measurements.
This was really informative, thanks! It's a snapshot of a very specific problem. But the way you present it, helped me to further familiarize myself with the inner workings of a vintage receiver. I own several units from the 70s, and a H/K 930 is one of them.
Thanks for the kind words, Mikko! The purpose of this channel is to share knowledge that I have learned from others, hopefully presented in a way that is accessible to a wide variety of viewers. BTW, are you Finnish?
@@kukko83 I'm in South Florida in the US. I moved from Miami to Palm beach county, pretty much the north end of South Florida, and the town I landed in has a fairly large Finnish expat community. I was in Helsinki a few years ago on vacation, and it was sunny all right. I think the temperature broke a record at 90°!
@@raygianelli3612 That's cool! The Finnish summers can be pretty hot sometimes, and to tell you the truth, anything over 25°C is getting to be too hot for me.🥵 The summers here are short though, only three months or so. A few years ago, I moved from a small town of Hämeenlinna (100km up north from Helsinki), to an even smaller town of Parola, about 10km further north. I have some very distant relatives in the state of Michigan, I think. But I've never heard much about them, other than what my late grand mother told me. I've always wanted to visit the US but haven't got around to do it yet. You're very welcome to visit Finland again!
I have a Marantz 2270 with the exact same issue: normal left channel, weak right. I’ll be sending it out to get worked on but it’s nice to know what the problem more than likely is; good video & thank you very much.
@@maxknittel1484 & Changing the volume pot remedied your problem? The issue mine has: normal sound out of left channel, weak sound out of right. The tests I have done: Using RCA cables, crisscrossed connection at the main in & pre-out and the speakers switched -meaning good sound out of right weak out of left. This was the same result whether using the main speaker jacks and button or the remote set up. Just to change things up, Using an RCA adapter, I hooked my iPhone up to the auxiliary ports- same result: good sound out of left, weak out of right. Also, while using headphones: left ear normal, right ear weak.
@@maxknittel1484 Interesting- even though the volume works fine when adjusting? Not questioning your diagnoses, just wondering how this all works.Part of the circuitry then I take it(?) I am a novice when it comes to electronics on stereo’s. I’ll put this in my notes as at some point, I’m gonna have a service technician that knows what they’re doing work on this receiver & I’ll pass on your remedy to them -although they already may know of it. Thank you👍
@@maxknittel1484 This unit was given to me years ago and I just recently fired it up and discovered the right channel problem. I don’t know if it had worked properly before I obtained it. It does need some restoration work done on it so I’ll be looking for a tech in CO.
You helped us lot sir.very nice to watch your videos. We learn a lot from thus easy way of learning. Thanks a lot and appreciate always your quality work and kind service.
I m an audiophile man having interest and knowledge of just basic electronic from last 30 years. I owned lots of resale vintage items just to check how sound reproduction of each amplifier (sound signature) changes with the circuit topology,brand,model,watts,type of final active device(IC,transistor,Moffett,tube)type of power supply for audio. I am always curious to find the secret to get most faithful audio reproduction at home system. I also learned importance of mic placement,speakers placement,loudness,compression,dynamic range,room reflections,ambient noise. Currently I hv vintage amplifier,cassette deck,cd player not so high end but medium level. As I confirm that recapping with good quality capacitors (elna,nichicon,Rubicon,black gate,mundrof)has sound improvement on my gears. I found most of recapping,restoration and repair videos helps a lot to me. Great to chat with you sir.
I really enjoy the way that you do these videos. As I follow along, I try to pinpoint the problem from your schematics before you find the solution. I was wrong in assuming that C534 had gone leaky and was reducing the gain. But it does make absolute sense that C504 had essentially gone open, causing the gain in that channel to INCREASE. Thank you for another enjoyable and though provoking video.
Surprised me too. But this is why I enjoy troubleshooting electronics so much. You start out in one place, and wind up somewhere else. I like that you're thinking ahead to try and surmise the issue. It really is fascinating, isn't it!
Great troubleshooting tips. I also have a VP-7725D but I think I need an owners and/or service manual for it to understand it better. Do have a PDF of either you could share? Thanks a lot!
Max, I do have a service manual. Let's see if I can post this: drive.google.com/file/d/0BxLVd1MVhl--ZTBMazRZd3RhWDg/view?usp=sharing&resourcekey=0-fJGtfju01wy38z6Flirk5Q
Own 2 of these 930. Most annoying were the poping noise during turn on and off. So I designed a simple time delay circuit and rerouted the speaker output through a relay. When turn on, the delay was set at 6 sec and cut out the relay immediately when turn off. Simple and effective solution. I recalled the FM stereo decoder was the MC1307 if I not mistaken.
Hi! How do you avoid melting the insulation when de-soldering hook up wires? Especially ones that are tightly wrapped around terminals. I've started to recap one of these but I feel I'm ruining the neat Japanese wiring by constantly melting or charring the insulation. Also, do you use foil or kapton tape in cramped areas where it's easy to hit loose wires with the hot soldering iron? I've done that too a few times now :|
Ivan, as far as wires on terminals the best approach is to simply cut them off, provided there is enough slack to do so. As far as other wires go, I either try to move them out of the way and ty-wrap them, or just exercise care. Wearing a magnifying visor helps too. If the wires look as thick as a pencil they're easier to avoid. The one thing I really worry about is melting a tuner string. Those I may cover with foil.
Hi Ray I just subscribed to your channel and I am still going through them and I enjoy your content and format. I have seen enough to know that I need to send you a little something and was wondering how I would do that and it would be a small package
Mike, that is so generous of you! I'm truly doing this to give back to the online community that taught me so much. Know that your offer is much appreciated!
Hey Ray, I have a problem on my HK 930, no AM or FM. I have not the tools you have (only a Fuke ans an old scope) Could you plse give me some ideas I have t check to repair this wonderful machine? Thx Geert
I forgot to mention that yesterday I happened to think of doing a search on RUclips for repairs to an HK930 and that's how I came across your channel. It's wonderful what you show there!
@@lindadepelecijn3985 Geert, nice to work with someone who knows a thing or two. Good job checking the voltage at those two points. Let me consult the schematic again and I will reply here. It will be later tonight (I'm in the US in the Eastern time zone).
Another nice video. Keep 'em coming! One small thing to note is that if you are going to chase a channel imbalance in the tone/preamp stage, make sure your balance is centered. Ask me how I know.
That sounds so much like something I'd do that I'm starting to wonder if we were separated at birth!
Seriously, that's a VERY important point. Appreciate you bringing it up!
Thank you for posting this video! I recently picked up an HK 930 that I need to replace the balance control pot as it's broken, i.e. the actual knob is missing. I had to use nose pliers to get to the center. That said, I tested it and noticed that there is definitely an audio imbalance as well. I'll replace the pot first and if it persists, then I will go down the same path you did, so thank you for showing me what to look for next!
Good luck, Joseph!
@@raygianelli3612 Just replaced the balance pot, and it's working perfectly now!! That said, do you know which caps/transistors are troublesome? I'd love to do a full restoration on this beauty.
@@jpreza Joseph, I only had that one for repair, so I can't say definitively which ones are issues. That said, most of this stuff is getting to the age where a blanket recap makes sense.
@@raygianelli3612 I just did a full recap over the weekend. The most difficult board was the main board behind the display. Pulling out the board for a recap would have required a full dismantling of the unit and I wasn't about to do that. Took me about 6 hours total. Glad it's done!
@@jpreza So, how does it sound?
13:45 I have a DATS V3 interface that I really haven't started playing with yet, and I wasn't aware it has such a detailed capacitor measurement function, so, now I need to explore it more. Thank you for the video, good stuff!
he mentioned this in another video and i thought the same thing. then i promptly forgot about it. now this video reminded me that i need to use dats to measure caps. as soon as i get this 2230 of the bench, i'm gonna measure some known bad and some brand new caps.
@@josephlalock8378 I'm thinking of creating some content on replacing the capacitors on.... my 2 air conditioning compressor units, as both have 15+ year old caps in them ( and I have the new replacements on hand already). I think it will make for an interesting test of the DATS data measurements.
This was really informative, thanks! It's a snapshot of a very specific problem. But the way you present it, helped me to further familiarize myself with the inner workings of a vintage receiver. I own several units from the 70s, and a H/K 930 is one of them.
Thanks for the kind words, Mikko! The purpose of this channel is to share knowledge that I have learned from others, hopefully presented in a way that is accessible to a wide variety of viewers.
BTW, are you Finnish?
@@raygianelli3612 Yeah, I am. Greetings from the snowy, and sunny Finland!
@@kukko83 I'm in South Florida in the US. I moved from Miami to Palm beach county, pretty much the north end of South Florida, and the town I landed in has a fairly large Finnish expat community.
I was in Helsinki a few years ago on vacation, and it was sunny all right. I think the temperature broke a record at 90°!
@@raygianelli3612 That's cool! The Finnish summers can be pretty hot sometimes, and to tell you the truth, anything over 25°C is getting to be too hot for me.🥵 The summers here are short though, only three months or so.
A few years ago, I moved from a small town of Hämeenlinna (100km up north from Helsinki), to an even smaller town of Parola, about 10km further north. I have some very distant relatives in the state of Michigan, I think. But I've never heard much about them, other than what my late grand mother told me.
I've always wanted to visit the US but haven't got around to do it yet. You're very welcome to visit Finland again!
I have a Marantz 2270 with the exact same issue: normal left channel, weak right.
I’ll be sending it out to get worked on but it’s nice to know what the problem more than likely is; good video & thank you very much.
I also have a 2270 that had channel inbalance problems. I had to replace the volume pot.
@@maxknittel1484
& Changing the volume pot remedied your problem?
The issue mine has: normal sound out of left channel, weak sound out of right.
The tests I have done:
Using RCA cables, crisscrossed connection at the main in & pre-out and the speakers switched -meaning good sound out of right weak out of left. This was the same result whether using the main speaker jacks and button or the remote set up.
Just to change things up, Using an RCA adapter, I hooked my iPhone up to the auxiliary ports- same result: good sound out of left, weak out of right.
Also, while using headphones: left ear normal, right ear weak.
@@richardmiller2313 Yes, it did.
@@maxknittel1484
Interesting- even though the volume works fine when adjusting? Not questioning your diagnoses, just wondering how this all works.Part of the circuitry then I take it(?)
I am a novice when it comes to electronics on stereo’s.
I’ll put this in my notes as at some point, I’m gonna have a service technician that knows what they’re doing work on this receiver & I’ll pass on your remedy to them -although they already may know of it.
Thank you👍
@@maxknittel1484
This unit was given to me years ago and I just recently fired it up and discovered the right channel problem.
I don’t know if it had worked properly before I obtained it.
It does need some restoration work done on it so I’ll be looking for a tech in CO.
Nice troubleshooting Ray, excellent. The visor thing I'm on that page as well, It's my best old man gear!
You helped us lot sir.very nice to watch your videos. We learn a lot from thus easy way of learning. Thanks a lot and appreciate always your quality work and kind service.
AMIT, thank you. This is the whole point of this channel, to share knowledge. Your comment confirms that my goal is being met.
@@raygianelli3612 ya confirmed sure.thanks a lot...
I m an audiophile man having interest and knowledge of just basic electronic from last 30 years. I owned lots of resale vintage items just to check how sound reproduction of each amplifier (sound signature) changes with the circuit topology,brand,model,watts,type of final active device(IC,transistor,Moffett,tube)type of power supply for audio.
I am always curious to find the secret to get most faithful audio reproduction at home system. I also learned importance of mic placement,speakers placement,loudness,compression,dynamic range,room reflections,ambient noise.
Currently I hv vintage amplifier,cassette deck,cd player not so high end but medium level. As I confirm that recapping with good quality capacitors (elna,nichicon,Rubicon,black gate,mundrof)has sound improvement on my gears. I found most of recapping,restoration and repair videos helps a lot to me. Great to chat with you sir.
I really enjoy the way that you do these videos. As I follow along, I try to pinpoint the problem from your schematics before you find the solution. I was wrong in assuming that C534 had gone leaky and was reducing the gain. But it does make absolute sense that C504 had essentially gone open, causing the gain in that channel to INCREASE. Thank you for another enjoyable and though provoking video.
Surprised me too. But this is why I enjoy troubleshooting electronics so much. You start out in one place, and wind up somewhere else.
I like that you're thinking ahead to try and surmise the issue. It really is fascinating, isn't it!
@@raygianelli3612 Yes it is. I get it right sometimes, other times I don't. But, that is part of the learning process.
Looks like you ae ready for a long hot summer! I have seen the same issue many times on Marantz 1030s and 1060s.
As usual excellent video of repairing stereo receiver.
Great troubleshooting tips. I also have a VP-7725D but I think I need an owners and/or service manual for it to understand it better. Do have a PDF of either you could share? Thanks a lot!
Max, I do have a service manual. Let's see if I can post this:
drive.google.com/file/d/0BxLVd1MVhl--ZTBMazRZd3RhWDg/view?usp=sharing&resourcekey=0-fJGtfju01wy38z6Flirk5Q
Own 2 of these 930. Most annoying were the poping noise during turn on and off. So I designed a simple time delay circuit and rerouted the speaker output through a relay. When turn on, the delay was set at 6 sec and cut out the relay immediately when turn off.
Simple and effective solution.
I recalled the FM stereo decoder was the MC1307 if I not mistaken.
I found some $15 protection boards from China that run on 120/240 VAC, Been using those for Adcom GFA-555 to add protection to them.
@@raygianelli3612 That was in the 70s when HK 930 was brand new.
Thank you again for a great education!
Thanks you, Brett! Comments like this one make my day, and really let's me know that this channel is achieving it's goal.
Nice lesson! For sure I would have focused my efforts on the weaker channel. Very good job 👍
Thanks! BTW you have a great channel. I'll be dropping by often. Oh, and I love the name, having a constantly messy bench myself. 😁
@@raygianelli3612 thank you!
Great job Ray. ❤
Thanks Ran. I enjoy this kind of work immensely, But this short break has been nice, TBH. 😁
@@raygianelli3612 A brake is always good for the minds and the soul 😉.
Hi! How do you avoid melting the insulation when de-soldering hook up wires? Especially ones that are tightly wrapped around terminals. I've started to recap one of these but I feel I'm ruining the neat Japanese wiring by constantly melting or charring the insulation. Also, do you use foil or kapton tape in cramped areas where it's easy to hit loose wires with the hot soldering iron? I've done that too a few times now :|
Ivan, as far as wires on terminals the best approach is to simply cut them off, provided there is enough slack to do so. As far as other wires go, I either try to move them out of the way and ty-wrap them, or just exercise care. Wearing a magnifying visor helps too. If the wires look as thick as a pencil they're easier to avoid.
The one thing I really worry about is melting a tuner string. Those I may cover with foil.
Hi Ray I just subscribed to your channel and I am still going through them and I enjoy your content and format. I have seen enough to know that I need to send you a little something and was wondering how I would do that and it would be a small package
Mike, that is so generous of you! I'm truly doing this to give back to the online community that taught me so much. Know that your offer is much appreciated!
Hey Ray, I have a problem on my HK 930, no AM or FM. I have not the tools you have (only a Fuke ans an old scope) Could you plse give me some ideas I have t check to repair this wonderful machine?
Thx Geert
Hi Geert! If both AM and FM are out I would start at the +12 volt supply, looks like the emitter of TR903 is the output of the +12 volt regulator.
Hi Ray, Thx for your quick answer. I have at the 'AM/FM front end' pin 5 - 12V and at pin 9 of the MC1307 also 12V.
I forgot to mention that yesterday I happened to think of doing a search on RUclips for repairs to an HK930 and that's how I came across your channel.
It's wonderful what you show there!
@@lindadepelecijn3985 Geert, nice to work with someone who knows a thing or two. Good job checking the voltage at those two points. Let me consult the schematic again and I will reply here. It will be later tonight (I'm in the US in the Eastern time zone).
@@raygianelli3612 Thanks a lot, Ray.