Does changing the capacitors make an audible difference?

George S.

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#21
Recapped some Fluke multimeters a while back. Double sided board so was easiest just to cut the old caps off above the base, pry the base off, then extract the leads from the circuit boards. Some of the caps were still well wet with fluid, so wet it actually squirted out on the board, some were dry. And it's corrosive, so the boards got cleaned. You never know what you'll find with electrolytics on old equipment.
 

Gepetto

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#22
It really depends on where they are used in the circuit. Power supply caps won't make much difference as long as they are still good and in spec,

Caps in the direct audio path are the ones you should be focusing on. Caps are often one of the most expensive components in equipment design so they are often the area sacrificed in order to cut costs. Many manufacturers are guilty of that. Stage to stage coupling caps in the audio path is likely the area that you may notice the biggest difference. Getting rid of electrolytics in those applications and replacing with film caps usually will produce noticeable differences since there is no global feedback utilized to minimize distortion in most preamp designs.

In my audio designs, I use WIMA exclusively for the film caps, Nichicon Muse exclusively for any power supply electrolytics and CDE Mica for the small value non-polar applications. Quality matters in terms of both sound and reliability.
 
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#24
It really depends on where they are used in the circuit. Power supply caps won't make much difference as long as they are still good and in spec,

Caps in the direct audio path are the ones you should be focusing on. Caps are often one of the most expensive components in equipment design so they are often the area sacrificed in order to cut costs. Many manufacturers are guilty of that. Stage to stage coupling caps in the audio path is likely the area that you may notice the biggest difference. Getting rid of electrolytics in those applications and replacing with film caps usually will produce noticeable differences since there is no global feedback utilized to minimize distortion in most preamp designs.

In my audio designs, I use WIMA exclusively for the film caps, Nichicon Muse exclusively for any power supply electrolytics and CDE Mica for the small value non-polar applications. Quality matters in terms of both sound and reliability.
Thanks for the post, and that's interesting. From what I understand my one deck does not have any capacitors in the output section, and they chose to eliminate them. I don't know what's in place, one of the text talked about it on YouTube but I forget what he said.
 

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#25
You can easily design without any caps in the direct audio pathway but most preamp type designs do not because it is simpler to interstage couple with capacitors.

Each interstage coupling has the capacity to introduce distortion since there is no circuitry that compares the input signal to the output signal (feedback vs open loop).
 
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#26
You can easily design without any caps in the direct audio pathway but most preamp type designs do not because it is simpler to interstage couple with capacitors.

Each interstage coupling has the capacity to introduce distortion since there is no circuitry that compares the input signal to the output signal (feedback vs open loop).
Hi,

what do you see in the pictures that I posted above, do you see all of the capacitors changed? And if so are they considered OEM or premium capacitors?
 

George S.

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#27
To me it looks well done by someone who knows caps and is thoughtful. I see Nichicon electrolytics, Panasonic films. If it's aligned, think it would sound as good or better than origonal.
On a piece of equipment that complicated, Teac, that use electronics to control mechanical assemblies, the original ceramics should stay unless their bad. They're not in the audio path and have a very long life. Start changing those out and bad things can happen quickly.
Looks like the power supply, and audio path electrolytics we're replaced. Not sure what they used in the power supply, but probably long life, high temperature caps. I see Nichicon FG and bipolars, and Panasonic films in what I presume is the audio path.
Don't know what more anyone would do on such a piece of complicated electromechanical equipment. If it works nicely, they did a good job! At least that's what I think.
Yes, the Nichicon FG "Fine Gold", bipolars, and Panasonic "ECW?" are very good audio grade.
 
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#28
To me it looks well done by someone who knows caps and is thoughtful. I see Nichicon electrolytics, Panasonic films. If it's aligned, think it would sound as good or better than origonal.
On a piece of equipment that complicated, Teac, that use electronics to control mechanical assemblies, the original ceramics should stay unless their bad. They're not in the audio path and have a very long life. Start changing those out and bad things can happen quickly.
Looks like the power supply, and audio path electrolytics we're replaced. Not sure what they used in the power supply, but probably long life, high temperature caps. I see Nichicon FG and bipolars, and Panasonic films in what I presume is the audio path.
Don't know what more anyone would do on such a piece of complicated electromechanical equipment. If it works nicely, they did a good job! At least that's what I think.
Yes, the Nichicon FG "Fine Gold", bipolars, and Panasonic "ECW?" are very good audio grade.
I appreciate you taking the time to look it over, thank you.

I live in the US, but this DEC came from Hungary, so it is a 220 V 50 Hz deck. I took a chance after I struck up a conversation online with the previous owner. As you know these are incredibly hard to work on, and most technicians/repair places won't even touch them. The previous owner assured me that everything was fully functional, and it is.

The only problem I'm having is the counter, and instead it seems to be running at about half speed so to speak. It counts every one second as 1/2 second, so when I get to the end of a 45 minute tape it says approximately 22 minutes on the counter.

I have it on a good power supply that not only changes the voltage, but it changes the frequency, and is running at 230 V 50 Hz perfectly.

it's been suggested that there is a bulb that may be too dim, and the Hungarian technician suggested I change the bulb out. I'm just not sure how to do that.
 

George S.

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#30
I would find the service manual to see if it has a dual primary transformer that can be rewired to US 110-120 VAC. All the later Phase Linear Series 2 gear came with such a transformer.
Or perhaps you can find the correct transformer in a cheap US parts unit. Many models for that year and series may share identical transformers.
The transformers secondary output should be identical, but check the service manual.
 
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#31
Is it real time counter or a stopwatch like Teac did in a lot of their 80's decks ?
Hi again. It's a regular counter, and I saw Videos before I bought it, and it seems to count just like any other deck does. Something is messed up with the lighting from what I understand, and I know it seems strange, but without the lights being correct it doesn't work properly.

I thought for sure it was the frequency in our electric here in the US, but from the onset I gave it a very good power supply with the correct voltage, and the correct frequency. It's a bit of a mystery but I need to get to the bottom of it.
 
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#32
I would find the service manual to see if it has a dual primary transformer that can be rewired to US 110-120 VAC. All the later Phase Linear Series 2 gear came with such a transformer.
Or perhaps you can find the correct transformer in a cheap US parts unit. Many models for that year and series may share identical transformers.
The transformers secondary output should be identical, but check the service manual.
Thanks for that suggestion, and I actually thought about doing the exact same thing. That is over my pay scale and I'm not comfortable doing it, and it's difficult to find anybody that will work on these. I hesitate to ship it, and my normal tech that is only a couple hours away may not service these.

I did see somewhere that it was switchable inside, but I think that was an international version and not the EU version like this is.
 
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#33
It's a bit of a mystery because I bought a really good power supply, and it just doesn't want to count rate. So far to text told me it's something to do with the lighting.
 

George S.

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#34
I've never worked on tape machines. Perhaps the tech is trying to say that if the lighting is not correct, then that is a good indication that the voltage and frequency conversion is not correct, therefore the tape counter will not work correctly.
 
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#35
I've never worked on tape machines. Perhaps the tech is trying to say that if the lighting is not correct, then that is a good indication that the voltage conversion is not correct, therefore the tape counter will not work correctly.
well one tech gave me an incomplete answer, that's the guy that worked on the machine over in Hungary. To the sellers credit he's going to bring his Z7000 into that tech and have him look into what kind of a bulb I need, and do some other diagnostics.

It's possible with the electric conversion that I am losing something, or rather that the machine is missing something. The other tech is the one that said the bulbs too dim replace it, I just don't know if I can do that myself or not.
 

George S.

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#36
I did just now look at Teac 6000 units on eBay. Very pricey and sophisticated machines. I find it unlikely that they would have designed a bulbs filament resistance into the tape counter circuit on such a machine, but, who knows.
I'm thinking the machine is sensitive to the needed 50 Hz AC cycle and just isn't seeing it. Your local guy should be able to verify your voltage adapter is working correctly.
First make sure it's not a international model that can be converted, then get the adapter checked, before going into the unit.
 

George S.

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#37
If the 50 Hz cycle it depends on is off frequency, then the tape counter counts may perhaps also be off "frequency". Best way I can describe it.
 
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#38
I did just now look at Teac 6000 units on eBay. Very pricey and sophisticated machines. I find it unlikely that they would have designed a bulbs filament resistance into the tape counter circuit on such a machine, but, who knows.
I'm thinking the machine is sensitive to the needed 50 Hz AC cycle and just isn't seeing it. Your local guy should be able to verify your voltage adapter is working correctly.
First make sure it's not a international model that can be converted, then get the adapter checked, before going into the unit.
I agree it seems very odd that they overlooked that. There was obviously a lot of R&D that went into this deck, this being said they did cheap out on some parts. The headphone and pitch control pots are junk, but they did get 99% of it right in my opinion. Absolutely built like a tank on a diecast frame and everything.

I need to figure the counter problem out because it's annoying more than anything else.

But maybe my electric conversion is not great like you suggested.
 
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George S.

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#39
I agree it seems very odd that they overlook that. There was obviously a lot of R&D that went into that, this being said they did cheap out on some parts. The headphone and pitch control pots are junk.

I need to figure it out because it's annoying more than anything.

But maybe my electric conversion is not great like you suggested.
Post a link to your AC adapter and the guys can look at it and comment what they think. That power supply voltage and frequency needs to be spot on for such a machine. Perhaps the motors control circuits can compensate for a frequency fault but the tape counter can't compensate as well. Let's see what adapter you have with a link.
 
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