So Close...Yet So Far [resolved]

[anthonynchandler]

Hmmm, not totally following you with where the cat 5 melting might be connecting, BUT:

On the Balance  I get a 77 on the top and a 66 on the bottom outer pairs of lugs
On the Volume  I get a 10 on the top and a10  on the bottom outer pairs of lugs

Not sure where to measure for the middle lugs of the volume pot, but from terminal 23 to middle lugs I get 0.

ACTUALLY in the 200 range I get a 2.0 on the middle lugs.

 

[Paul Joppa]

Are you confident that your cables are in the correct RCA jacks?  If all the voltages are good, it'll be something pretty simple like this.

Your post #20000!!!

 

[anthonynchandler]

At this rate I may be Paul's #25000 and #30000.

I gave it a rest last night, but I am afraid we are still with no sound.

Any more ideas on what to do next?

Many thanks,
Anthony

 

[Paul Birkeland]

The first thing to do is to get a meter that can measure low AC voltages.  This one looks fine and isn't too expensive:
https://www.amazon.com/AstroAI-Multimeter-Resistance-Transistors-Temperature/dp/B071JL6LLL/ref=sr_1_1_sspa?crid=33V3Y6WMBFOUH&dib=eyJ2IjoiMSJ9.0igT1Raq2QuSN2cSijNtPcSoCFfxOvx2OVUSjP30cWAYY1Q3-oK75-p8bZRBjrAIlbsVzJ3Wpq1OLklw65bsG8GuWib9FLbjE_eflH3oul5IgOkxofdLMuDET5qwdd6iZ4hiog0QQdFkQOezw8tjrfekHiZSTwAiDotLuDkOzcqZr0SnjcKNZYs_t84ic62bI7Gix58thh8uKi2eSdzMeCmTdX38fsmL3G4x9UPwC2DPXiJa2imGHc_TE_afTSkS6XKNc8JE2iEErpSnqlJVOzSqCAqTXvos7iSVccjXJ1I.Li9MpJnkJmhtn6ukfUL0GTAEni6PNJ8Q5iOT2IPBLlo&dib_tag=se&keywords=digital%2Bvolt%2Bmeter&qid=1739068248&sprefix=digital%2Bvolt%2Bmet%2Caps%2C186&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

You'll need some device with a headphone jack and an 1/8" TRS to RCA cable.  This can be a laptop, phone, or tablet, and you'll either use a signal generator app or just a web based 60Hz test tone on that device to shoot signal into your Moreplay.

When you have those devices, we can start tracing signal in your preamp.

 

[anthonynchandler]

Ha ha ha...I KNEW I would need a different multimeter sooner rather than later!  I had that one to help with with some house electrical jobs.  The AstroAI is definitely priced right. Alright, I will order one and then see what we can discover. 


I should have the cable with appropriate signal maker.

Many thanks,
Anthony

 

[anthonynchandler]

Paul,
I have the signal 60hz, the connection from my phone to rca and the new multimeter arrived.
Where do I begin?

Thanks
Anthony

 

[Paul Birkeland]

Start by playing a 60Hz tone from your source with the 1/8" to RCA cable plugged in.  Be sure to turn the volume all the way up!  Now take your new meter and set it to AC volts and use the probes to measure across one of the male RCA plugs, and let us know what that AC voltage is. 

-PB

 

[anthonynchandler]

Paul,
If I plug in the 60hz source  to input 1, turn all volumes up, turn on the Moreplay and then measure across any of the RCA inputs [if you mean red to red rca and black to black rca on the same input].
then the ranging numbers go immediately to 0.

If I just touch the red probe to a red rca, then I get between 0.998 and 1.2

A

 

[kgoss]

Put the black probe on the rca ground and the red probe on the rca center pin/cup.

 

[Paul Birkeland]

No, this is a test to measure your device, the Moreplay is not to be used for this first test.  Just plug the cable into whatever source is making the 60Hz tone, then measure the voltage across the male end of the cable when it isn't plugged into anything.  It's important to know this number first.

 

[anthonynchandler]

Okay...sorry for being slow on this procedure. Hmmm, so if I measure AC volts just on the end of the source RCA then the number ranges a lot. I definitely do not get a simple number.
Maybe it helps me if I know where to place the red and black probes for each measurement.

If I connect my red probe to the centre pin of the red rca on the signal cord and touch the black probe to the outer sleeve of the same rca, then I get .809

Thanks, Ken!
Even though these probably mean nothing as I have no reference, this is what I got.


RCA 1 -  0.685

RCA 2 - 0.808

RCA 3 - 0.807

RCA 4 - 0.804

RCA 5 - 0.  when I go to ground, but 0.857 when just the red probe

 

[Paul Birkeland]

OK, so now you can plug the RCA plugs into the Moreplay.  I would put them in input #2.  Start with the selector switch set to 1 or 3, then measure the AC voltage across each RCA jack on input 2.  (Black probe on shell, red probe on the center pin for each jack). 

If you still see about 0.8V, then put the selector switch on input 2 and recheck.

If you still see about 0.8V, then measure the AC volts between ground in the amp and the red wire leaving the selector switch, as well as ground in the amp and the white wire leaving the selector switch (ground in the amp is any black wire on either the balance pot or ground pot).

If you still see about 0.8V, then measure the AC voltage at each of the middle lugs of the balance pot with the balance pot about centered.  It will be less than 0.8V. 

None of these tests require the Moreplay to be powered up, and I'd suggest leaving the power cord unplugged for now since it just isn't necessary.

-PB

 

[anthonynchandler]

Paul,
With the input going into Input 2, here are my cacophony of readings. Not sure if this helps us at all  :-\ 


Selector Switch to 1
Input 1
Red 85v
Black 73V

Input 2
Red 0.8V
Black 0.8V

Input 3
Red 0V
Black 0V

Selector Switch to 2
Input 1
Red 60V
Black 143V

Input 2
Red 0.8V
Black 0.8V

Input 3
Red 107V
Black 0.8V

Selector Switch to 3
Input 1
Red 0V
Black 0V

Input 2
Red 0.8
Black 0.8

Input 3
Red 115V
Black It builds to 125 and ranges a lot

• AC volts between ground in the amp and the red wire leaving the selector switch. 0V
• ground in the amp and the white wire leaving the selector switch 0V
• AC voltage at each of the middle lugs of the balance pot with the balance pot about centered. 0V

 

[Paul Birkeland]

Input 2
Red 0.8V
Black 0.8V

This is what we want.

• AC volts between ground in the amp and the red wire leaving the selector switch. 0V
• ground in the amp and the white wire leaving the selector switch 0V
• AC voltage at each of the middle lugs of the balance pot with the balance pot about centered. 0V

Is this with the selector set on input #2?

 

[anthonynchandler]

I believe so, but I can confirm shortly.

 

[anthonynchandler]

No, the selector must not have been on 2

Here are the current readings

•  AC volts between ground in the amp and the red wire leaving the selector switch. 0801V
•  ground in the amp and the white wire leaving the selector switch 0.801V
•  AC voltage at each of the middle lugs of the balance pot with the balance pot about centered. 

Bottom Center      0.707V
Top Center    407V

 

[Paul Birkeland]

You have 407V coming out of the selector switch? Hopefully that's 0.407 and 0.707, that's about 5dB off, but the bigger deal is that the signal is present at the output of the volume pot. 

Next you will want to do this same testing but measure on pins 5 and 6 on each 8 pin socket. Assuming you still see about the same readings there, then you'd power up the Moreplay and measure the AC voltages at terminals 9 and 19 with the signal playing into the preamp.

 

[anthonynchandler]

Paul,
No sorry. That was my fault with trying to type the numbers when I cannot see the screen with the questions -sigh.

I have 0.807 V on both the red and white wires off of the selector.

 

[anthonynchandler]

Paul,

5/6 on the A channel is 0.632V, but on the B channel I am getting that same 535V on the 5/6 [and it is 535V versus 0.535V]

On terminal 9 it is 3.746V.  and on terminal 19 it is 2.964V

 

[anthonynchandler]

Still no resolution on getting sound of my Moreplay, but it certainly looks nice next to my Crack build.

Any more ideas on what I might check next to see why sound does not appear?

Many thanks!
Anthony