What is the value of this variable resistor ?

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Hi,

I currently restore a GOLDMUND Mimesis 3 amplifier, and I have to change this variable resistor (see attached photo):

mini_191121045237146706.jpg
[/url][/IMG]

The following references are written on the part:

64Y 201
R601


Do you know what is the exact value: 200ohms, 600ohms ?

Thank you
P.S.: I know that I could measure it after desoldering, but as I am about to place an order for the other parts, I prefer to include this R with the order...
 
AX tech editor
Joined 2002
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Hi,

I currently restore a GOLDMUND Mimesis 3 amplifier, and I have to change this variable resistor (see attached photo):

mini_191121045237146706.jpg
[/url][/IMG]

The following references are written on the part:

64Y 201
R601


Do you know what is the exact value: 200ohms, 600ohms ?

Thank you
P.S.: I know that I could measure it after desoldering, but as I am about to place an order for the other parts, I prefer to include this R with the order...

Seems 200 ohms, that is the typical way of labelling. You can measure without desoldering that will give you a close enough indication.

Jan
 
AX tech editor
Joined 2002
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Thak you Jan , I also believe it is this value...



If I measure it without desoldering, the measured value should normally be impacted by the circuit it is connected to, shouldn't it ??

Hardly. The measurement current is small, and even if it isn't absolutely accurate, it's enough to see if it is 200R or 600R. Did you try?

BTW If this is connected as a rheostat (wiper connected to one side) make sure to record the position, then turn it to one side fully, then measure, then reset to value ;-)

Jan
 
Did you try?

Not yet, but I will tomorrow : it has been a nightmare to open this device, but I finally succeeded...

Sometimes I believe that the manufacturer has done everything possible to make the maintenance as difficult as possible....


Why do you have to change the VR if it's not broken?

Because I used to work with an engineer for restoring vintage devices, and he cannot get the amp stable because of a faulty VR.

I will change them, as I used to do these tasks very often...

Thank you
 
AX tech editor
Joined 2002
Paid Member
That is extremely unusual. You should be prepared for the fact that there actually is another issue.

Again, it is a no-brainer to verify if the VR still works as it should with a simple resistance meeting. Measure the resistance while turning it will very quickly show if there is a short or open.

Jan
 
The measurement current is small, and even if it isn't absolutely accurate, it's enough to see if it is 200R or 600R. Did you try?

Here are the measurement I performed this morning (without desoldering):

LEFT channel:
pin1 -> pin2 = 122 ohms
pin1 -> pin3 = 219 ohms

RIGHT channel:
pin1 -> pin2 = 113 ohms
pin1 -> pin3 = 202 ohms

So this let me think that this variable resistor is 200 ohms...
 
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Mark is correct. There are build threads for this good old amplifier here on diyaudio.
That also shows a 200 ohm'ish trim for offset adjustment.

On the schematic posted by forr just after your reply , the variable resistor is 200 ohms, not 220 ohms.

I have bought and received 200 ohms variable resistors and when I have time to desolder the original ones, I will measure them (to tune the new ones to the same value than the original): I hope that I can use the 200ohms resistors that I have received !??

Thanks
 
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