Vintage hifi

[J4CKO]

nigelpugh7 said:

J4CKO said:

Well, I got the KEF speakers and hooked one up and tested it, sounded alright and switched left to right to compare, definitely an improvement.

Did the right one and turned it back off, sounded a bit weird briefly and then no sound whatsoever.

Nothing on any input, have I killed it ?

Any suggestions as to how to test ? Guessing it might be output transistors or something, unit still works otherwise just no sound at all.

Don’t want to bin it.

It’s normally the output transistors that have developed a fault.

They are quite easy to replace, if you can get new versions or their equivalent.

You just need a multimeter to check for shorts or open circuits.

This might help.

https://youtu.be/Gc9s03wstRk

Have fun!

Cheers Nigel, watching it now, got a multimeter and a decent soldering iron etc, have done caps in power supplies and stuff before

[TonyRPH]

J4CKO said:

Well, I got the KEF speakers and hooked one up and tested it, sounded alright and switched left to right to compare, definitely an improvement.

Did the right one and turned it back off, sounded a bit weird briefly and then no sound whatsoever.

Nothing on any input, have I killed it ?

Any suggestions as to how to test ? Guessing it might be output transistors or something, unit still works otherwise just no sound at all.

Don’t want to bin it.

At a guess, I'd say that one of your new speakers has a damaged (near short circuit) woofer, and the sound you were hearing was from the tweeter only.

And then the amp didn't like the heavy load, and either blew a fuse (many Rotel products of that era used fuses in the speaker lines for protection) - or - the amplifier itself has blown on that channel.

Using a meter on the ohms range, measure across the terminals of the suspect speaker. It should be somewhere in the range of 4 - 8 ohms.

ETA: Just checked the schematic - there is a power supply fuse for each channel - F601 / F602 - I would check those for a start.

I've highlighted the fuses in the schematic below (only one channel is shown - but both fuses are visible).

Be sure to check the speaker as I described above before connecting it again.

Edited by TonyRPH on Thursday 10th March 12:57

[nigelpugh7]

TonyRPH said:

At a guess, I'd say that one of your new speakers has a damaged (near short circuit) woofer, and the sound you were hearing was from the tweeter only.

And then the amp didn't like the heavy load, and either blew a fuse (many Rotel products of that era used fuses in the speaker lines for protection) - or - the amplifier itself has blown on that channel.

Using a meter on the ohms range, measure across the terminals of the suspect speaker. It should be somewhere in the range of 4 - 8 ohms.

ETA: Just checked the schematic - there is a power supply fuse for each channel - F601 / F602 - I would check those for a start.

I've highlighted the fuses in the schematic below (only one channel is shown - but both fuses are visible).

Be sure to check the speaker as I described above before connecting it again.

Edited by TonyRPH on Thursday 10th March 12:57

Yep Tony that’s a great point, forgot about output fuses!

Of course check those first, and if it’s just those blow then you’re lucky and can find out if the speaker has a short before reconnecting it!

[J4CKO]

TonyRPH said:

J4CKO said:

Well, I got the KEF speakers and hooked one up and tested it, sounded alright and switched left to right to compare, definitely an improvement.

Did the right one and turned it back off, sounded a bit weird briefly and then no sound whatsoever.

Nothing on any input, have I killed it ?

Any suggestions as to how to test ? Guessing it might be output transistors or something, unit still works otherwise just no sound at all.

Don’t want to bin it.

At a guess, I'd say that one of your new speakers has a damaged (near short circuit) woofer, and the sound you were hearing was from the tweeter only.

And then the amp didn't like the heavy load, and either blew a fuse (many Rotel products of that era used fuses in the speaker lines for protection) - or - the amplifier itself has blown on that channel.

Using a meter on the ohms range, measure across the terminals of the suspect speaker. It should be somewhere in the range of 4 - 8 ohms.

ETA: Just checked the schematic - there is a power supply fuse for each channel - F601 / F602 - I would check those for a start.

I've highlighted the fuses in the schematic below (only one channel is shown - but both fuses are visible).

Be sure to check the speaker as I described above before connecting it again.

Edited by TonyRPH on Thursday 10th March 12:57

Whoa, thats awesome, will get it down and have a look over the weekend, going to keep it one way or another as even thought its not the original from my childhood it doesnt seem to matter. Will be checking the speaker for sure, seller was mate of a mate and had these from new in the eighties so dont think he had any idea, you win some you lose some. I was actually upset about it, think its the old mentality of when things broke, couldnt afford to fix them but nowadays can easily afford a replacement or repair, but will try and sort it myself, much more satisying, and cheaper.

But have found myself looking at other vinatage hifi, what looked old and crap now looks fantastic. There is a spare Denon mini system going but that now looks like the seventies silver monoliths did when that first came out.

[nigelpugh7]

TonyRPH said:

At a guess, I'd say that one of your new speakers has a damaged (near short circuit) woofer, and the sound you were hearing was from the tweeter only.

And then the amp didn't like the heavy load, and either blew a fuse (many Rotel products of that era used fuses in the speaker lines for protection) - or - the amplifier itself has blown on that channel.

Using a meter on the ohms range, measure across the terminals of the suspect speaker. It should be somewhere in the range of 4 - 8 ohms.

ETA: Just checked the schematic - there is a power supply fuse for each channel - F601 / F602 - I would check those for a start.

I've highlighted the fuses in the schematic below (only one channel is shown - but both fuses are visible).

Be sure to check the speaker as I described above before connecting it again.

Edited by TonyRPH on Thursday 10th March 12:57

Yep Tony that’s a great point, forgot about output fuses!

Of course check those first, and if it’s just those blow then you’re lucky and can find out if the speaker has a short before reconnecting it!

[J4CKO]

Checked the speaker and seem to be ok, put them onto a tiny, cheapChinese amp and few in my bluetooth dongle and they work fine, all the fuses inside seem fine also.

[TonyRPH]

Did you have any wayward strands in your speaker cable perhaps?

Anything that could have caused a short?

Does the Rotel work with the original speakers, or is it still not happy?

[J4CKO]

TonyRPH said:

Did you have any wayward strands in your speaker cable perhaps?

Anything that could have caused a short?

Does the Rotel work with the original speakers, or is it still not happy?

Dont think I did, would that take out both channels in one fell swoop ?

Am keeping it as a longer term project but am looking for something else, I had a Technics amp in the early nineties and cant remember the model name but by god it was a monster, it had a volume control in the middle from what I remember and was quite deep so looking for something similar. It was outrageous the wallop it had so fancy something along those lines. Have made an offer on one on eBay and also a set for £100 on FB marketplace but aprt from a "Yes" to my question as to whether he would accept my price, not heard anything.

I foolishly sold it for a Dolby Pro Logic Technics amp which was lame in comparison, but had a remote control that made the volume knob turn magically, but oh my god the sound was a disappointment. Always seems to be a theme with surround amps for music stuff, never seem to quite as good, got Sony STR DN-1080 surround amp and its alright, better than the ste Onkyo I had but never seems to be that impressive for a reputed 130 Watts per channel amp.

[J4CKO]

I got bored with SH stuff and dealing with folk with unrealistic expectations, £200 for a 30 year old amp, stuff on sale for £200 that was covered in thick dust, ffs give it a wipe ! Stuff with faults like "Bit Crackly on one channel", i.e. its probably skip fodder.

Got on Richer Sounds and ordered this,

https://www.richersounds.com/yamaha-dab-bluetooth-...

Brand new, warranty, more than enough power for a small garage, DAB, Bluetooth so dont have to fiddle around with shonky Chinese BT adaptor.

[nigelpugh7]

J4CKO said:

I got bored with SH stuff and dealing with folk with unrealistic expectations, £200 for a 30 year old amp, stuff on sale for £200 that was covered in thick dust, ffs give it a wipe ! Stuff with faults like "Bit Crackly on one channel", i.e. its probably skip fodder.

Got on Richer Sounds and ordered this,

https://www.richersounds.com/yamaha-dab-bluetooth-...

Brand new, warranty, more than enough power for a small garage, DAB, Bluetooth so dont have to fiddle around with shonky Chinese BT adaptor.

I did pretty much the same back in June last year.

We had the predecessor to this, but the tuner had started to play up, so got the new version with Dab+ and Internet radio.

It was £233, when I bought it, but now it seems that are £399!

The best thing is the MusicCast system, used with our devices and the great iOS app, it’s used all around the house, and I use the internet radio more than anything else too!

[J4CKO]

nigelpugh7 said:

J4CKO said:

I got bored with SH stuff and dealing with folk with unrealistic expectations, £200 for a 30 year old amp, stuff on sale for £200 that was covered in thick dust, ffs give it a wipe ! Stuff with faults like "Bit Crackly on one channel", i.e. its probably skip fodder.

Got on Richer Sounds and ordered this,

https://www.richersounds.com/yamaha-dab-bluetooth-...

Brand new, warranty, more than enough power for a small garage, DAB, Bluetooth so dont have to fiddle around with shonky Chinese BT adaptor.

I did pretty much the same back in June last year.

We had the predecessor to this, but the tuner had started to play up, so got the new version with Dab+ and Internet radio.

It was £233, when I bought it, but now it seems that are £399!

The best thing is the MusicCast system, used with our devices and the great iOS app, it’s used all around the house, and I use the internet radio more than anything else too!

Yeah, can see this is £50 dearer than it was, the US review I saw had it as $149 in 2020, so no illusions its a very budget amp but its for my tiny garage so will be plenty, just want the convenience of BT.

[Crackie]

My first ever amp was one of these, purchased with cash earned from a lot of gardening and lugging golf clubs around the local course 45 years ago. I still have it and this thread has inspired me to get it up and running again........if only to see the VU meters dancing again.

[CorradoTDI]

Crackie said:

My first ever amp was one of these, purchased with cash earned from a lot of gardening and lugging golf clubs around the local course 45 years ago. I still have it and this thread has inspired me to get it up and running again........if only to see the VU meters dancing again.

Love the symmetry and simplicity of that!

[alabbasi]

Very cool. I love me some VU meters

[Dr Nookie]

snowandrocks said:

Just got my 70's Yamaha CA-610 connected up after it was in for a little repair. Sounding lovely and hopefully now good for another 50 years of service.

Really need to track down the YP-511 turntable I've promised myself before they get any more expensive and I'll get things set up properly.

That is quite the piece...fantastic.

[Arranguez]

Love the Sony ES stuff. I’ve got one of those high end Walkman’s, was it a DD9 or something? I used it to rip some cassettes onto MP3 a few years ago. It had Dolby C and everything!

I’ve got a few older bits like a SACD Sony and some Linn amp kit which is just gathering dust. I thought yesterday I really ought to sell it. It won’t ever be setup again properly I expect.

[Mars]

alabbasi said:

Very cool. I love me some VU meters

Yeah, me too - what's the brand/model? I'd love to find one of those on eBay.

[TonyRPH]

Mars said:

alabbasi said:

Very cool. I love me some VU meters

Yeah, me too - what's the brand/model? I'd love to find one of those on eBay.

It's a Proton - might be an AA1150

They are quite rare so you'll be lucky to find one....

[Mars]

TonyRPH said:

Mars said:

alabbasi said:

Very cool. I love me some VU meters

Yeah, me too - what's the brand/model? I'd love to find one of those on eBay.

It's a Proton - might be an AA1150

They are quite rare so you'll be lucky to find one....

Thanks. I do love the look of it and I've not found any other brand/model that looks as good as that.

I'm a sucker for pretty displays.

[alabbasi]

Mars said:

Yeah, me too - what's the brand/model? I'd love to find one of those on eBay.

It's an Onkyo Integra M-5060R. I was looking for an M506 or M508 which are more common in the US and ran across this one which is a dual voltage model so I decided that it would be a good buy if I ever move back to the UK.
It's driving a set of KEF 105.4's

The beast next to it is a B&K EX442 amp / Pro 5 preamp driving a pair of Magnapan MG1's

It's a new hobby for me but I might have already got carried away.