Steremour almost complete

crackaddict · 3425

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Offline crackaddict

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on: August 25, 2014, 02:52:32 PM
Hi,

I’m almost done with my Stereomour build. I diverged from the manual in just a few places, and I thought I'd get final "approval" before powering on tonight when I make the final connections.

- I split the output from the input selector and routed one leg to the third set of RCA jacks, so I can connect my Crack to output 3. Plenty of discussion on this in the forums, so I should be OK.

- I connected the short black wire from B9 in the 9-pin tube socket to 10L instead of 8L (page 45). Later pictures in the manual show this (the switch happens somewhere between page 51 and 59), and I get why! 8L gets pretty crowded with the drain wires. Certainly no issues here.

- But I made one tiny change which was not shown in pictures or discussed in the forums: in connecting the AC mains, I chose to use the 5” black 24AWG wire cut off from the STP to twist around the red wire and connect transformer terminal 8 to N on the power entry module (page 49 of the manual). I did this purely for aesthetic reasons: the other twisted pairs look so nice, I wanted to have an “evenly matched twisted pair” for this application as well. I figured most of the mains wiring is already this 24AWG STP wire, so this would not hurt. Am I OK keeping this, or should I replace with the 20AWG wire called for in the instructions?

Oh, one last question. When I do resistance and voltage checks, does it matter how I have the input selector, volume pot, or hum balance pots set?

Thanks,
Derek



Offline crackaddict

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Reply #1 on: August 26, 2014, 09:36:19 PM
Hi all,

So my build is complete, with impedance selector switch upgrade and all. Resistance and voltage checks ok. But it's still silent: I don't have speaker cables yet! I sure can't wait to turn this thing on and hear my Orcas and Dungeonness for the first time.

Derek



Offline Grainger49

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Reply #2 on: August 27, 2014, 12:41:35 AM
Derek,

You can visit the hardware store and buy some 16 AWG lamp cord while waiting for the audio grade wire to arrive.  It is so much better than sitting in silence.



Offline crackaddict

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Reply #3 on: August 27, 2014, 10:10:14 AM
Good idea! I have to swing by to get a few replacement screws for the impedance switch anyway.
Derek



Offline crackaddict

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Reply #4 on: September 07, 2014, 03:15:38 PM
Hi again,

So I finished my Steremour, but a few questions remain. I thought I'd turn to this group to figure out if everything is OK.

1) Connecting it to my Orcas (not yet the Dungeonness -- I'm still waiting on that cable...), there's a funny thing going on when I turn the amp on. I would normally turn on my amp with volume at zero, but in order to figure out what's going on, I turn on the audio source first (in this case a Sonos Connect going into an Arcam rDAC, given that I haven't finished my Reduction yet). With the volume at twelve o'clock, I turn the amp on. The right channel comes up nicely from quiet to full volume in perhaps 5 seconds. The left channel, on the other hand, has a very audible low hum with no music coming through. Then, about the time the right channel comes in, the hum stops, as if a switch were being thrown, and the music starts. This does not appear to affect listening once warmed up, but it does not seem right, and I like to have things right...

2) I assumed things would be a bit louder. Sitting with my Orcas on my desk in near-field mode (about 36" away from my Orcas, which are separated by about 48"), I have the volume at 12:00 or 1:00, listening to "radio" on my Sonos or MP3s via the DAC. I did switch to the Alps Blue Velvet 100K audio taper pot...). Does it seem about right to have the pot at 12:00 sitting so close to the amp? Maybe I'm trying to hear more, which the sub would bring out...

3) The voltage checks were all within 5%-10%, reading high if anything. The resistance checks were all good, although terminals 2 and 14, which "may settle around 486K ohms," were up in the 13M ohm range and moving very, very slowly, so I did not "let them settle" -- does this seem right?

4) The input selector switch makes an audible click when switching with the volume up. Normal?

5) When only one channel is connected to an audio source, and that audio source is active, I can hear it faintly when moving the selector switch to another source, with volume at 12:00. Is a bit of cross-talk normal?

I was super careful with all my solder joints, and I've re-inspected everything. I use a Weller soldering station set to 675 degrees. On the PCBs, I re-touched each joint to make sure contacts were good. I can always check again, but I think I'm good in terms of solder joints.

Thanks for any help!
Derek



Offline crackaddict

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Reply #5 on: September 07, 2014, 03:17:57 PM
PS I have the impedance selector switches set to medium-high (which I understand equates to 8 ohms), balanced.



Offline fullheadofnothing

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Reply #6 on: September 07, 2014, 05:48:55 PM
1) Noises while warming up are normal.

2) The position of the line on the knob is arbitrary. As long you have sufficient sound level for what you the position of the knob doesn't matter. If it really bugs you, move the knob on the shaft so it points wherever you want.

3) Fine.

4) Fine.

5) Fine.


Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus


Offline crackaddict

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Reply #7 on: September 08, 2014, 06:38:30 AM
OK, all should be good, then. Getting my sub cable in the post this week, and wrapping up my Seduction soon, so I'm almost at the home stretch!

Thanks,
Derek