Amp Camp Amp - ACA

[vdi_nenna]

I'm trying to finish up an order from Mouser and can find everything except for R12. It's listed as a 68.1K, 0.4W resistor. You can find them at Digikey (Invalid Request) but, unfortunately, they're only sold in quantities of 5000 at Mouser. Can someone point me to a proper alternative from Mouser? Thanks in advance.

How about these? You did say .4w, correct? How about just using a 1w 68.1k?

http://www.mouser.com/Passive-Components/Resistors/_/N-5g9nZscv7?P=1yzeg3qZ1z0wsz3Z1z0z819

 

[dodog]

This worked for me.

68.1 K Resistor

Thanks for that link.

I saw that one but was worried that the rating is 250 mW while the BOM is looking for 400 mW. Is this safe to use or should I look for another option?

 

[bcmbob]

I'm not an expert, but as I said, that one worked in my build. I have another pair of resistors that is slightly out of spec which makes me believe the amp design can tolerate some variance in parts. Others may be able to give you a better - more technical answer.

 

[dodog]

I'm not an expert, but as I said, that one worked in my build. I have another pair of resistors that is slightly out of spec which makes me believe the amp design can tolerate some variance in parts. Others may be able to give you a better - more technical answer.

Understood. I'm not an expert either, which is why I worry about swapping parts without understanding the consequences. I do appreciate your help though.

Can anyone weigh in on this and why this may/may not be a good idea? Are resistors like capacitors where you can safely up the voltage specs (within reason) when swapping parts or is it the opposite (lowering the voltage specs). Further, where R12 is in the circuit, does a mini jump in specs make much of a difference, for longevity and safety's sake?

 

[N Brock]

You can use the CMF55 parts with no issue.

If they're run at a half watt (which they aren't in this case) with 70°C ambient they will drift at most ±1%. Not a problem in this circuit.

Some of the first ACA kits went out with all CMF55 signal resistors.

 

[dodog]

Thank you N-Brock and bcmbob!

 

[bcmbob]

 

[WalterW]

Thanks for that link.

I saw that one but was worried that the rating is 250 mW while the BOM is looking for 400 mW. Is this safe to use or should I look for another option?

Even 0.25 Watt is safe in this position.

Walter

 

[Confucius]

My ACA, All in one PCB.

I build my PCB, and use this ACA for my headphone.

 

[toobhed]

Hi Folks,
...finishing up the wood chassis to the ACA and would like to use two blue LEDs that would be the same size, specs etc as the red ones that come in the ACA kit. Any suggestions? Appreciatively,
Mario

 

[speedless]

Hi
I need some help,I finally found nearly all the bits for the ACA#1,exept a replacement type for ZTX450 ?
and the "silk" caps.
I cant find them here in Denmark! (!"#¤%&/()=?!""#¤#)!!!
(Sorry for my french)
I might be able to get ZTX451,will it do ? They look almost identical on the data sheets.
Will standard electrolyte caps sound awfull ?
If I overlooked posts about any of this,sorry.So many infos here for my old twisted mind.

Jan

PS:Again,sorry for my french and english !

 

[Zen Mod]

instead of ZTX use any of BC variety - not critical ; BC546 or BC550 (any suffix) , for instance;different pinout from ZTX

define standard electrolytic ; if made by decent producer , that's decent in my book

 

[Variac]

"Papa" Pass uses Panasonics in other locations including the output cap..
The differences are quite subtle. If you want to feel better leave some of the leads showing above the board so if you want to change them someday you can clip them off and desolder easily. You won't of course- the ACAs sound so good!

Incidentally they do seem to be affected by speaker choice a lot. You get the right combo and you just can't stop listening..

Nice to see that you're bilingual

Mark

 

[speedless]

Hi
Zen Mod
Nice quick and precise answer.Thanks
Didnt think the type of q3 was critical but you never know with audioholic designers
The caps;alu type,I can get ELKO low resistence types ?
Whats more I just found that DIGIKEY has a Danish site.
Seems they have all the bits and I dont have to trouble the forum with boring questions.
(Not a promise)

Jan

PS:Is there a tread on the "Parallel" version?

 

[speedless]

Hi
Just to inform any one living in EU and having a hard time getting there bits and pieces.
Try DIGIKEY´s site.
Normally I would not advertice for anyone,but compare the product index,prices and shipment terms/price.
Just ordered the parts for the ACA and some for the PLH.
Waiting for that magic moment: "Your order has been send"

Jan

PS:

PS:Is there a tread on the "Parallel" version?

Meant the parellel version of the PLH.

 

[mat1976]

now this is a nice amp for my son to start on.
only thing i can not find (i think i am just a bit blind) are the specs on the psu.
most parts i have laying around in my junk box.
not knowing much of electronics i never got around to using them.
but now i finished my aleph 5 mono blocks and having seen the joy in my sons eyes while helping me, i think it is time to let him start his own project.
sorry, i have no pictures of it, but he is not yet 5 and already soldered about 1/3 of the alephs.

 

[billyk]

PSU are switching power supplies suitable for laptops. 19v at about 4 amps. I'm using two old Dell supplies from defunct laptops.

 

[mat1976]

that is all???

great, i have plenty of those laying around.

my son is gonna be one happy little camper

thanks for the info.

 

[6L6]

Yes. 19V laptop power supplies.

 

[mat1976]

well, i've been checking my junk boxes and found all but the ZTX450 ,but i already have seen zen mod mention a other possibility, and 2 resistors, the rest i have.

so i just have to design and build the chassis and i've got my son's 5th birthday present ready for him to solder.