John Curl's Blowtorch preamplifier part II

[marce]

Got it a through hole rivet, now I understand....
very 70's

 

[keantoken]

I use these 40 step resistive attenuators. They're quite nice and have a feel as good or better than the Seiden switches. They've eliminated the wiper contact by using a highly flexible wire.

An externally hosted image should be here but it was not working when we last tested it.

se

I am imagining the mechanism, and it sounds like an interesting idea. You could probably even mod it into a stock pot. I'll have to try that...

 

[simon7000]

Got it a through hole rivet, now I understand....
very 70's

Bob Pease used to have a thing about them. On his first job at Philbrick the eyelets would cause failures by thermal movement tearing the copper foil.

I suspect that since they are still around they may have fixed that issue.

 

[AudioLapDance]

...Pease's book on analog troubleshooting should be required reading for anyone putting their hands into a piece of electronics.

If I was a circuit, I'd behave!

http://www.amazon.com/Troubleshooting-Analog-Circuits-Series-Engineers/dp/0750694998

 

[Steve Eddy]

I am imagining the mechanism, and it sounds like an interesting idea. You could probably even mod it into a stock pot. I'll have to try that...

What do you mean by mod it into a stock pot?

EDIT: Oh, do you mean mod a stock pot to eliminate the wiper contact?

se

 

[SY]

SY, the schematics that you have should be adequate to allow you to repair the Vendetta easier, but it is not the EXACT schematic of the unit you have. You have a B, and the schematic is of an A.

Interesting- the unit is marked as an A. What changes did you make?

 

[AudioLapDance]

...Pease's book on analog troubleshooting should be required reading for anyone putting their hands into a piece of electronics.








If I was a circuit, I'd behave!

Troubleshooting Analog Circuits (EDN Series for Design Engineers): Robert Pease: 9780750694995: Amazon.com: Books

 

[dvv]

Got it a through hole rivet, now I understand....
very 70's

Perhaps, but it prevents poor soldering connections rather well.

 

[marce]

The rest of the electronics world struggles with normal PCBs and normal PTH holes, no need for outdated techniques really, but this is audio an I believe sometimes that certain areas of audio exists in the twilight zone

 

[vacuphile]

acoustic-dimension attenuators

Dan.

Wonderful world, to learn from an Australian that this fine Dutch product exists.

 

[31697B]

As I usually do, I pick up specific test equipment to learn and see what affects this/that have then get rid of it. For jitter, I have on order the Yokogawa TA320. It will measure jitter and give a distribution plot.... down to +/- 100pSec full scale. I will see what i have and how to improve it.... also what makes it worse and how much worse. Enough about what perfect communications theory and other such ideal conditions and the like says. I'm sure to learn a lot about all sorts of things with it re jitter.



THx-RNMarsh

 

[anatech]

Perhaps, but it prevents poor soldering connections rather well.

oh, I don't know. Just ask Philips about the first couple generations of CD players that had solder connection problems with their "griblets". Their terminology, not mine.

-Chris

 

[keantoken]

What do you mean by mod it into a stock pot?

EDIT: Oh, do you mean mod a stock pot to eliminate the wiper contact?

se

Yep. Might not even need a flexible wire.

 

[Elvee]

I am imagining the mechanism, and it sounds like an interesting idea. You could probably even mod it into a stock pot. I'll have to try that...

Membrane potentiometer?
Sensor Design to Meet the Rigors of Space Satellites

 

[Steve Eddy]

Wonderful world, to learn from an Australian that this fine Dutch product exists.

It's actually Korean. But I'm not at liberty to say any more.

se

 

[wrinkle]

Perhaps, but it prevents poor soldering connections rather well.

There is/was a Marconi spectrum analyser, quite a good spec, but had hundreds of those eyelets, after a while they usually went bad, and some poor technician would have to spend a couple of days or so soldering them all up to get rid of the intermittent issues they caused.

 

[elektroj]

As I usually do, I pick up specific test equipment to learn and see what affects this/that have then get rid of it. For jitter, I have on order the Yokogawa TA320. It will measure jitter and give a distribution plot.... down to +/- 100pSec full scale.

I'd love to see what you will find out with it. I had TA320 for some time but wasn't completely satisfied with it - not enough resolution for my needs. I later upgraded to TA520 (still have it), but it also doesn't have enough resolution to measure jitter in tens of pSec range.

 

[Jay]

It's actually Korean. But I'm not at liberty to say any more.

se

True. You cannot change the statement to "Wonderful world, to learn from an Australian that this fine Korean product exists" because it would have different meaning

 

[SY]

The problem with eyelets is the PCB- difference of the coefficient of thermal expansion and creep between PCB and metal are not conducive to long term reliability.

 

[jacco vermeulen]

this fine Dutch product

The model offered by Acoustic Dimension up till a couple of years ago was powder coated in blue.
Oldy page from the site, on the top : Volume control main page, 41 step attenuator, Amtrans, Audio Note, TKD 2CP-2511
Identical to the ones manufactured by Allnic in Korea, if you're lucky the name of the manufacturer is even in copper on the boards inside.(I have a couple of the prettier ones)