An other boomer soon to leave the barn

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Veteran and General Yakker
Joined
Apr 12, 2012
Messages
5,815
Location
SoCal
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Survived the Thomas fire
#42
Are the single conductors tin plated, or raw copper? (I’d like more color selection)
Silver coated copper - only have the 10 standard colors. Also have single conductor shielded cables but only one color.
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
2,669
Location
Connecticut
#43
Ohhhh! Silver!

(place pinky to corner of mouth)

I think I’ll get some here soon…

Edit- by “more color selection” I meant more than I have now with my tin plated wire, not that I was asking for more from you.
 

grapplesaw

Veteran and General Yakker
Joined
Aug 13, 2014
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Vancouver
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---
#47
So new update. Only had time to populate the outputs Yesterda. I do them all a one time now.

today set up for testing. Set out with dim build and all sorts of meters hooked up.

now to be humble
i started the varic and as I bought up at about 30 volts the unit was drawing about 1 amp. This is not right so as I thought about it the neg 1/2 watt left channel fuse blue on the back plain. This was troubling as everything had gone text book perfect. The funny thing is I powered to fully without fuses and no fuss. Spent 2 hours checking my work and perplexed as to who this came to be. Well it was operator error. The meter I used for the measure negative supply voltage on the control board had probes connected to it prior to testing. I replace them with a mini grabber setup. I plugged into the amp circuit instead of the everything else circuit. Well that’s behind me and the rest of testing went well.
so here are the numbers.
right channel

dc offset .40 mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.67 v &@120 v 56.6 v
output distortion .006 thd+n
residual noise connected to 8 ohm load and 1k on imput 172uv. And 120uv without 8 ohm load


left channel


dc offset .22mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.42 v &@120 v 56.1v
output distortion .0068 thd+n
residual noise connected to 8 ohm load and 1k on imput 190uv. And 135uv without 8 ohm load


so this may be the quietest amp I’ve built. thanks to some tips along the way.
shout out to Joe who had added an extra fuse in my order. What a guy.
 

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Gepetto

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Staff member
Joined
May 15, 2011
Messages
10,191
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#50
So new update. Only had time to populate the outputs Yesterda. I do them all a one time now.

today set up for testing. Set out with dim build and all sorts of meters hooked up.

now to be humble
i started the varic and as I bought up at about 30 volts the unit was drawing about 1 amp. This is not right so as I thought about it the neg 1/2 watt left channel fuse blue on the back plain. This was troubling as everything had gone text book perfect. The funny thing is I powered to fully without fuses and no fuss. Spent 2 hours checking my work and perplexed as to who this came to be. Well it was operator error. The meter I used for the measure negative supply voltage on the control board had probes connected to it prior to testing. I replace them with a mini grabber setup. I plugged into the amp circuit instead of the everything else circuit. Well that’s behind me and the rest of testing went well.
so here are the numbers.
right channel

dc offset .40 mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.67 v &@120 v 56.6 v
output distortion .006 thd+n
residual noise connected to 8 ohm load and 1k on imput 172uv. And 120uv without 8 ohm load


left channel


dc offset .22mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.42 v &@120 v 56.1v
output distortion .0068 thd+n
residual noise connected to 8 ohm load and 1k on imput 190uv. And 135uv without 8 ohm load


so this may be the quietest amp I’ve built. thanks to some tips along the way.
shout out to Joe who had added an extra fuse in my order. What a guy.
Hi Glen
You are a testimony to wire dress mattering. It really does. If you want a really quiet amp, it comes down to sensible wire routing and dress.
 
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