Doug Self's New Preamp Construction and Pictures

[calpe]

stocktrader, there are numerous posts based on this Preamplifier 2012 (Elektor April, May & June 2012 issues), you'll find the diagrams there.

 

[calpe]

More.... Input PCBs with ribbon cable and some custom 2-pin interconnects.

Redjr, may i ask about the ribbon cable and connectors you have used?
Ideally, i would like to have a similar set up as yours with the Left & Right input pcb's, one above the other.
What connectors and cable have you used to connect the two K17 sockets together?
This cable then connects to K1 on the Front Panel pcb.
Thanks

 

[Kay Pirinha]

I can't see how this preamp would outperform mine @ 110db CD / AUX signal / noise and virtually no op amp distortion. , plus tube warmth and musicality.

Would you like to share your schematics, please, best in a new thread?

Thanks in advance!

 

[calpe]

redjr, also what are the other connecting cables you have used

 

[deltalight]

What is your source for the smaller 3/8" nuts used for the pots you mentioned??

Good work and thanks for the photos!

 

[calpe]

I need to check on Monday

 

[calpe]

Ive only just been able to get back to this very delayed Preamplifier project.
Ive emailed Schaeffer AG: Home in the hope they can do the work i need for the drilling etc.
Let's see

 

[calpe]

What is your source for the smaller 3/8" nuts used for the pots you mentioned??

Are these the 1W Dual 1K Pots? http://export.farnell.com/vishay/14920f0gjsx13102ka/potentiometer-1w-dual-1k/dp/8557314?ost=8557314&iscrfnonsku=false&ddkey=http%3Aen-EX%2FElement14_Export%2Fsearch

See the data sheet http://www.farnell.com/datasheets/439095.pdf

 

[calpe]

I am using the R.S. case 665-7719 | PF-19 Ventilated Rackmount Enclosure with Handles, 2U, 84 HP, 245mm Deep |

Might anyone having used this case have the Front Panel Designer files they used?

With thanks

 

[calpe]

http://www.diyaudio.com/forums/chip-...ml#post5202416

If i'm to use the Front Panel Designer files from post 18, then based on muskyhuntr's post 6, i would like to ask about the following:-

Power On/Off switch used and order number?

Toggle Switches used for: -
Tone Defeat
MM / MC
IEC Amendment

Mains input socket (i need 240v) used and order number?

With thanks

 

[calpe]

Hi redjr,
How did your wiring go?

Was there any changes to the list you made?

Thanks

 

[calpe]

I have finally been able to get back to this project build after so long.

Can anyone please give me any advise and steps that i should take and be aware of when doing the wiring?

Are there straight forward guides available of all the connections, including the d.c. connections?

With thanks
Calpe

 

[dennismiller55]

I used Harwin connectors available through Mouser.

Headers & Wire Housings

Contacts to match

Use the Series Number M20 to find "number of positions"

And I bought this crimping tool on Amazon:

Engineer Inc PA-20 Precise Universal Wire Terminal Crimping Tool

You can get these connectors and crimper tools on eBay as well.

 

[dennismiller55]

For dc connections I just use salvaged PC desktop hook-up wire. Three color coded wires twisted together.

 

[calpe]

Cheers dennismiller55. I actually have variations of these : -

http://uk.farnell.com/harwin/m20-1180042/crimp-socket-gold-22-30awg-pk100/dp/1022219?ost=681-2878&iscrfnonsku=true&ddkey=http%3Aen-GB%2FElement14_United_Kingdom%2Fsearch

http://uk.farnell.com/harwin/m20-1060300/crimp-housing-3way/dp/865618?ost=681-2821&iscrfnonsku=true&ddkey=http%3Aen-GB%2FElement14_United_Kingdom%2Fsearch

I just wanted to be 100% sure how clear it is when connecting the pcb's together from all the connection points.

Thanks

 

[calpe]

My build

My very slow build up to now with just paper labels indicating controls...

Wiring to do.....

 

[dennismiller55]

Did you notice the Harwin connector housing has pin 1 marked with an arrow. Just make sure you follow the same wire pattern on each end of the cable. Most of the connections from one board to the next is pin specific. The silk screening on the board will guide you.

 

[calpe]

Cant check now until Monday, but thanks for the advise

 

[calpe]

Dennis plz see your P.M.

Just to mention to the late builders (like me) the NE5532's that were available when i purchased them were the NE5532AP.

http://uk.farnell.com/texas-instruments/ne5532ap/op-amp-dual-low-noise-5532-dip8/dp/1106091?ost=NE5532AP&ddkey=http%3Aen-GB%2FElement14_United_Kingdom%2Fsearch

You'll see here the supply voltage range is +5v - 15v.
The Elektor project has 17v supplies from the PSU.

In the above technical sheet for this i.c. it shows max. voltage is 22v, but recommended supply is 15v.

I wrote to Elektor explaining this and they told me to play it safe reduce R2 & R4 from 1.3k to 1.1k, which i have done, reducing the PSU o/p from 17 to 15v.

I'm playing it safe.

 

[calpe]

In Elektor 06-2012, page 26, it give information of 'Miscellaneous - Not on PCB'.
Can someone clear up what is written of the fuse F1 (230VAC) = fuse, 0.315A Antisurge?

What is the correct mains input fuse that should be used on the mains input circuit?