parts list for forsell opto comp

[peter purpose]

[quote author="ChuckD"]
Which of these opamps can be used?

990 www.johnhardyco.com [$46.00]
992 www.forsselltech.com [$65.00]
JLM99 www.jlmaudio.com [$54.50]


-ChuckD[/quote]

All of the above can be used, but as this is essentialy a Fred Forssell design, I think it would be respectful for those of us who can afford Fred's op amps to support Fred in buying his products.

peter

 

[TomWaterman]

Hi again!

ChuckD - from scanning over the board again (I may have the wrong version?), it appears that its a case of one or the other output amp, and unless I'm mistaken, the Forssell output stage is also capacitively coupled to the output??? I thought this wasn't needed as its a servo design....

So, does anyone fancy getting some Forssell DLR-1s for the input buffers?

I think the price is $39.95, with a small price break at 10Pcs and another one at a higher total...I think it can get as low as $32.95......

Cheers Tom

 

[babyhead]

Forum-

I can't wait to make these!

Can we use the:

http://www.forsselltech.com/JMP-1.htm

in either position?

-Thanks!

 

[TomWaterman]

Hi babyhead,

The JMP-1 is a fully fledged microphone amplifier and would not be needed in the opto project.

Your looking at either a DLR-1 or 992/3 opamp for the input buffer and another 992/3 for the make-up gain stage.....they are a lot less expensive than the JMP-1, which actually feuatures three 992/3s inside the potted mic amp.

Hope that helps

Cheers Tom

 

[DrFrankencopter]

I'm in for 4 DLR-1's if a group order materializes....

Cheers,

Kris

 

[pucho812]

does anyone have a schematic and the PCB layout/ PCB blank for this?

 

[FredForssell]

Hey everyone...

You know, I'm really blown away at the response to this whole compressor project thing. I think it's really great that everyone is putting so much effort into making it all happen. I hope you all are as happy with the opto compressor as I have been. I look forward to hearing how the various designs work out in actual use.

For those of you who missed out on the group buy of FET-992s, I am willing to offer reduced rates if you buy at least two JFET-992, JFET-993 or DLR-1s. Take 10% off and round down. That's your price. Please email me (don't PM) at [email protected] and mention this posting in your email if you are interested.

On second thought, perhaps this should have been posted in "The Blackmarket" rather than "The Lab". Sorry about that.

 

[Flatpicker]

[quote author="FredForssell"]...On second thought, perhaps this should have been posted in "The Blackmarket" rather than "The Lab"...[/quote]No, here is good. I might have missed it otherwise! :shock:

 

[babyhead]

The JMP-1 is a fully fledged microphone amplifier and would not be needed in the opto project.

I hit the wrong link. I'm talking about the DLR-1...

-Thanks

 

[ChuckD]

Thanks Frank! That sounds like a more then fair deal to me...
OK with the OP amp question out of the way lets move on to the IRON.

What models of some good 1:1 600ohm transformers are folks using?
Sources? Prices?

What about a Lundhal
LL5402 (used in Gyraf Pultec) www.cablefactory.com $50 USD each

Any others?

-ChuckD

 

[TomWaterman]

Hi Fred!!

Thats an awesome offer! Thanks a lot.

So I'd need 2 DLR-1 amps.

Dr.Frankencopter = 4

Thats 6 so far @ $35.96 (10% off)

BTW - I have been in contact with www.primeled.com for another project I'm working on (these are the meters used in the DangerousMQ etc).

They have a really nice 10-step LED ladder that is massive. Its 50mm long and each L.E.D segment is 3.86 by 7.75mm. They are two thirds down this page...

http://www.primeled.com/bargraphdetails.htm

They are tri-colour LEDs so I guess you could set them to whatever colour you want, red, green or orange. I think they will be really nice for large visual GR display....I'm planning a dual comp in a 2U box - they would fit vertically this way or horizontally in 1U.

They are $5.75 each @ 1-10 and $5.45 @ 11-99.

Maybe people are interested in a group buy of these as well - they are not much more expensive when compared to the kingbright / agilent 10-packs at Farnell.

What do people think?

Cheers Tom

 

[wilebee]

I'd take 4

Wil

Wilebee

 

[TomWaterman]

Hi!

4 of which the DLR-1 or the LEDs?

Cheers Tom

 

[wilebee]

sorry led's I already talked to fred about the dlr's

Wil

Wilebee

 

[tommytones]

1st off, Flo, check your e-mail as I've sent you the revised schems which my layout and parts list is based. This should help answer most of your questions.

those are 12uf 35v elcos. But this value is very uncommon so i am wondering if two 10uf 35v are ok ?

Yup..

RV1 is a 10k pot i guess. But linear or logarithmic ? Don't know what's the A-suffix in 10k_A although i guess it's about linear/logarithmic.

LOG

Any tips on which kind of output transformer for the NE5534 output section ? I'd like to get something from OEP because i can get them and they are cheap (and not bad)

You name it. There's plenty of room for experimentation here.

The 48V power transformer i guess is a 2x24V transformer right ?

48V ct (center tapped). 2x 24v would work also.

Is there a way for a stereo unit to just stuff one board with the onboard section of the psu and from there feed the regulated voltages to the other board or does every channel have to be fitted with the onboard psu section ?

You can distribute regulated dc to more than one board if you wish but it kind of defeats the purpose of having individual psu per pcb. You can in fact build one off board regulated psu and feed numerous boards without using the onboard psu at all. I've trid to make this as versatile as possible while maintaining the big picture.

I have one question, that I can't quite figure out from looking at the boards....is there a jumper selection needed to select fred or butta's output stage?

I was thinking about the possibility of adding a toggle switch and populating both amps, to have a hifi/vintage switch for tonal variation? Or is it just a case of one or the other?

Would that be possible from the board layout?

This can be acheived but would require cutting some traces on the pcb. As it is, it's one or the other. I don't think it would be too difficult though if you really wanted to have this option.

and unless I'm mistaken, the Forssell output stage is also capacitively coupled to the output??? I thought this wasn't needed as its a servo design

That cap is from the other output circuit.

 

[TomWaterman]

Thanks for the clarification Tom - I'll investigate it all when we get our boards!!

Wilebee - I'll contact prime led about the meters and see what gives....I'm in the UK, they and you(?) are in the US, not sure how that will work out with shipping as I'll be ordering some other stuff from them and it seems crazy to ship it here and then back again.

Cheers Tom

 

[Infernal_Death]

Thanks for the infos, Tom.
I just uploaded the rest of the files you just send me. Here they are:

http://mitglied.lycos.de/InfernalDeath/Bendo_Buffer%20copy.jpg

http://mitglied.lycos.de/InfernalDeath/Fopto-2.pdf

http://mitglied.lycos.de/InfernalDeath/Fopto-2_Input_Buffer.jpg

http://mitglied.lycos.de/InfernalDeath/OptoMeter2%20copy.jpg

http://mitglied.lycos.de/InfernalDeath/Output%20copy.jpg

http://mitglied.lycos.de/InfernalDeath/PSU%20copy.jpg

http://mitglied.lycos.de/InfernalDeath/SideChain_revB%20copy.jpg

The pdf is the new board layout with the added stereo link.

Flo

 

[tommytones]

Thanks Flo. I'm gonna clean up the PSU and Input Buffer schem when I get a minute but you have all the info I used.

 

[Svart]

i have a new BOM to add to this thread if anyone can host it.


:thumb:

 

[Gustav]

[quote author="Infernal_Death"]Ok Tripod is back up so i could upload the parts list.
You can find it here:
http://mitglied.lycos.de/InfernalDeath/Forssell_Opto_Parts_rev1.pdf

I just hope it will be available for a while without going down again.

Flo[/quote]

Cant access the file, anyone wanna share?

Gustav[a]lavfrekvent.dk

I could host a copy if needed.

Gustav