[Verde And Black]

Arrrgh.

Need some help with a new, sudden issue with troubleshooting vinyl playback.

Got back from a work trip to Atlanta tonight. Had a few hours post work before I needed to head to the airport and did a little crate digging at a couple of really good record stores.

Anyway, got home, poured myself a single malt and dropped one of the new platters on the deck and there was audible distortion. Checked the record, checked and cleaned the stylus, all was good.

No better on restart.

Tried a record I listened to the night before I left with no issues, same problem.

The chain:
Sources:
U-Turn Orbit Plus turntable, low hours Ortofon Red Cart
No Sim Card iPhone 8 as dedicated streamer over WiFi
Cayin CD Mini MK 2

U-Turn is run into a Mani 2
iPhone is connected to Modi 3e via apple camera adapter
Cayin is connected to Modi 3e via coax.

Integrated 10wpc Tube Amp into Klipsch RP-600M II speakers.

Amp has a phono in and one line level input.

Modi and Mani are connected to a SYS that is used as a switcher into the line level input.

On closer examination, when the SYS button is set for the Mani, there’s audible noise from the speakers that increases in volume with the volume pot on the amp, and goes away the moment the SYS is switched to the digital input.

A quick check of the cables from the turntable into the phono-in on the amp and no noise

So, best I can tell, I either have, somehow, developed some kind of ground loop that didn’t exist before or something has gone wonky with the Mani 2.

Thoughts?

 

[adias]

Does your tonearm have a ground wire? Is that connected to the Mani 2 ground contact?

 

[Verde And Black]

Does your tonearm have a ground wire? Is that connected to the Mani 2 ground contact?

The U-Turn is supposed to be internally grounded.

From their FAQ “How do I ground your turntables? The Orbit is internally grounded through the shielding of the left RCA output, so no external ground wire is needed (even if your phono preamp has a ground screw or terminal).”

What’s odd to me is that quite literally nothing has changed regarding phono playback since Monday night when it worked flawlessly (as it has for many months now).

Edit to add: if I disconnect the rca from the turntable into the Mani and switch the SYS to the Mani position, there is obvious, scratchy static from the speakers that goes up and down in level in relation to the volume pot.

 

[adias]

Is there also pot noise on the other sys channel. If yes, it sounds like a bad pot.

 

[Verde And Black]

Is there also pot noise on the other sys channel. If yes, it sounds like a bad pot.

No noise on the digital in on the SYS. Happily listening to some streaming tunes through it as I type.

 

[adias]

Have you flipped the sys inputs? Dies the problem change to the other input?

 

[Verde And Black]

Have you flipped the sys inputs? Dies the problem change to the other input?

I have not. Will check that in the AM, but I’m more concerned by the noise coming from the Mani when no input is coming into it.

 

[A Jedi]

Just an fyi,

The Orbit is internally grounded through the shielding of the left RCA output

Not all RCA cables have the shield connected at both ends. If your cable has directional arrows, it doesn't.

 

[adias]

Just an fyi,



Not all RCA cables have the shield connected at both ends. If your cable has directional arrows, it doesn't.

Good point! He may have connected the cables differently this time.

 

[Alcophone]

Flatheads, and all the others come in many different head types. The slanted, counter-sinkable(?) is but one of many….

Sorry, I'm not a native English speaker, so I learned about these terms late in life.

Are you saying slotted screws can be called flat heads, i.e. are you talking about the drive type, independent of the head shape?



Because I've mainly seen flat head as the name for the countersunk head shape, vs. the common pan head, button head, etc. types.



I figured the idea is that the head is flush with the surface, and therefore flat.

For some reason these appear to be called flat head as well, maybe because they are low profile and flat-ish, just not flush.



Put differently, Schiit uses flat head Phillips screws.

 

[tincanear]

Arrrgh.

Need some help with a new, sudden issue with troubleshooting vinyl playback.

Got back from a work trip to Atlanta tonight. Had a few hours post work before I needed to head to the airport and did a little crate digging at a couple of really good record stores.

Anyway, got home, poured myself a single malt and dropped one of the new platters on the deck and there was audible distortion. Checked the record, checked and cleaned the stylus, all was good.

No better on restart.

Tried a record I listened to the night before I left with no issues, same problem.

The chain:
Sources:
U-Turn Orbit Plus turntable, low hours Ortofon Red Cart
No Sim Card iPhone 8 as dedicated streamer over WiFi
Cayin CD Mini MK 2

U-Turn is run into a Mani 2
iPhone is connected to Modi 3e via apple camera adapter
Cayin is connected to Modi 3e via coax.

Integrated 10wpc Tube Amp into Klipsch RP-600M II speakers.

Amp has a phono in and one line level input.

Modi and Mani are connected to a SYS that is used as a switcher into the line level input.

On closer examination, when the SYS button is set for the Mani, there’s audible noise from the speakers that increases in volume with the volume pot on the amp, and goes away the moment the SYS is switched to the digital input.

A quick check of the cables from the turntable into the phono-in on the amp and no noise

So, best I can tell, I either have, somehow, developed some kind of ground loop that didn’t exist before or something has gone wonky with the Mani 2.

Thoughts?

Did mani gain & cartridge loading switches on the underside get inadvertently changed from your normal settings?

 

[Andrew Randle]

1. Another tube to chase down.
2. Even more heat.
3. In my experience, I haven't noticed any particular magic associated with tube rectifiers vs solid-state in actual implementation.
4. Our power supplies are frequently much more complex than a single rail--so how would you feel about 5-7 tube rectifiers?
5. Even as a single, they're pricey.

6. Space

Andrew

 

[Verde And Black]

Good point! He may have connected the cables differently this time.

No changes to cable orientation.

System was powered down on Monday night, not touched for four days, and powered up tonight.

Only started futzing with cables when issues happened tonight.

 

[tafens]

The 12 o'clock positioning of the dial should roughly equate to that 'step 63-64' midpoint right? I wonder if there is just some physical transition point there that sometimes manifests itself as a pop in the speakers, for whatever not-understood electrical reason? Hmm...

It makes kind of sense that there could be a pop from step 63 to step 64, assuming that resistors with increasing values are switched in/out in a binary scheme. As 63 in binary is 0111111 and 64 is 1000000 that would be 7 connections changing at once. Because in reality all of them doesn’t change at exactly the same time there is potentially a small split of a second where all or none are connected, possibly producing a slight pop as that would be a big change in volume (for that split of a second until all connections are firm). In the same way there could be a similar but smaller pop from 31 to 32, 15 to 16, etc, at any power of 2.

To avoid an issue like that one can use a variation of binary code known as Gray-code where only one connection ever changes at any one step.

(Being a programmer by trade my brain couldn’t avoid noticing the connection of step 63 to 64 on a stepped attenuator and binary code; also, sorry if this has been talked about already - I’m currently catching up on the thread, only 4 days behind now! )

 

[bcowen]

Look what I found!

Sweet! Here's a later version Weston after refurbishing. While I'm partial to Hickoks, the Westons were beautifully built and more rugged than most portable testers of the time.