completed chipamp pre

[maf_au]

Originally posted by Russ White
[..]
And use the image from post #3 to guide you.

R3 and R4 are correct on the board(and on the image I refer to) they were just not correct in my initial old BOM.

The BOM on post #101 is correct if you need the cap values.

Cheers! [/B]

Got it! Thanks I'm now unconfused

Michael

[VT67]

Hi Russ

All the boards are finished!
Next step is to give them a decent home. Didn't found anything useful up to now. Is it a wise idea to put some cap's on the outputs to block out any DC? To attenuate the volume I only have a blue 100K Alps stereo pot and two mono cermet 50K Bourns potmeters at hand. I guess the 50K's are preferred here or should I go even to a lower value?

Regards

[Russ White]

Originally posted by GeWa
Hi Russ

All the boards are finished!
Next step is to give them a decent home. Didn't found anything useful up to now. Is it a wise idea to put some cap's on the outputs to block out any DC? To attenuate the volume I only have a blue 100K Alps stereo pot and two mono cermet 50K Bourns potmeters at hand. I guess the 50K's are preferred here or should I go even to a lower value?

Regards

As long as there is no DC on the input there will be none(or next to none) on output. If you think you might have a source with DC, I would put a ~2.2uf cap directly after your 100K alps pot. I have had better success with 10K stero pots, but the 100K should work fine. I really like the little 9mm 10K stereo pots Jaycar sells.

You could put a cap on output if you like, but you should not need to. I would just check for DC on the output when you power it up connected to your source, but not your power amp.

Cheers!
Russ

PS, I hope you get a chance to hear it soon!!!

[maf_au]

Mine are finished apart from a couple of 10pf ceramics and a couple of 2pin headers.

Here they are overlaid on a piece of paper the size of the box I have selected.

With a bit of wiring and mucking around, should be going in a day or so...

[Russ White]

Originally posted by maf_au
Mine are finished apart from a couple of 10pf ceramics and a couple of 2pin headers.

Here they are overlaid on a piece of paper the size of the box I have selected.

With a bit of wiring and mucking around, should be going in a day or so...

You can safely omit all of the ceramics on the freebird, and the RF filter 10pf on the yardbird if you are itching to test it.

Looking good man!

Cheers!
Russ

[maf_au]

Yardbirds are full house, I thought the 10pf on the freebird sounded like a good idea, already decided to omit the 20pf C5/C11.

With my tranny, I have dual secondaries. How should I connect that to the 3 input pins on the PS? It's a Jaycar MT2086 15-0 0-15v

Regards,

[Russ White]

According to the scpec sheet on Jaycar's site for that trafo, you would join the red and white leads (4 and 5) so that the two secondaries are in series, you then would run a tap wire where you joined those two wires, that is your center tap now, and will be your GND. The two remaining secondary leads (3 and 6, yellow, and purple) are your AC1 and AC2.

That trafo should work out very well.

Cheers!
Russ

[VT67]

Free- and Yardbirds popping up all over the place now!
Gonna see if I can lay my hands on a 50 or 10K stereo pot first before I continue. Maybe another dumb question but which type of potmeter is best as a volume attenuator, linear or logarithmic?

Cheers

[Russ White]

Originally posted by GeWa
Free- and Yardbirds popping up all over the place now!
Gonna see if I can lay my hands on a 50 or 10K stereo pot first before I continue. Maybe another dumb question but which type of potmeter is best as a volume attenuator, linear or logarithmic?

Cheers

Hmmm which is better is a difficult question...

But I prefer to use a good log pot. I like the 10K alpha stereo log pots from Jaycar a lot, they have a great taper, and sound to me better than the alps. And they are about $5.00US apiece.


Cheers!
Russ

[maf_au]

Thanks Russ,

And while I'm getting my newbie training,

What's the best way of crimping these mini crimp pin connectors? (my pliers are too big) Fine needle-nose, or is there a special tool?

Do you solder them as well?