• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

12AX7 Preamp NOOB Question

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hey! I have my schematics and I have my parts list. I just don't know exactly what type/brand ect of these parts to buy or where to find them. I did find some "Audio Grade" Radial Caps on one site but trying to find the caps that match the project pic is killing me.

What are PC electrolytic caps? I still haven't figured that one out. I can find metallised polyester but there are so many different types. Radial, Epoxy coated, Shrink wrapped plastic, ect...

My main question is. Where can I find the correct parts for the project below.

Thanks,
Mace


Project picture and Schematic http://diyaudioprojects.com/Tubes/12AX7_Preamp/index.htm

Parts List
CAPACITORS
1 220uF 10/16v PC electrolytic
1 47uF 450v PC electrolytic
2 220nF (0.22uF) 630v metallised polyester (greencap)
1 100nF (0.1uF) 100v metallised polyester (greencap)
1 100nF (0.1uF) 630v (greencap)


RESISTORS (0.25wt 1% metal film )
3 1M
2 33k
2 100k 1wt carbon film
2 1k
1 8.2k
 
Mace_Hacker said:
Hey! I have my schematics and I have my parts list. I just don't know exactly what type/brand ect of these parts to buy or where to find them. I did find some "Audio Grade" Radial Caps on one site but trying to find the caps that match the project pic is killing me.

Don't worry about it.

What are PC electrolytic caps?

Printed Circuit board mountable electrolytics. These have the two leads coming out of the same end, as opposed to coming out of each end (axial capacitors). This doesn't matter, since both types work just the same. For my projects, I use what's called a "modified dead bug" method of making the subsystem circuit boards. Onehelluvalot easier than a printed board, and easily amenable to parts on hand.

I still haven't figured that one out. I can find metallised polyester but there are so many different types. Radial, Epoxy coated, Shrink wrapped plastic, ect...

My main question is. Where can I find the correct parts for the project below.

Again, this really isn't such a big concern. I prefer AuriCaps myself (it may be "overkill" in projects that use gNFB) Solens are also quite good. Polypropylene dielectrics are almost as distortion-free as free space. You can find perfectly good capacitors from the Mouser catalog. Since this project does incorporate gNFB, whatever errors that the more common polyesters may produce will be corrected by the negative feedback loop. There are lots worse contributions to inferior open loop design than capacitors. Of course, in a design that doesn't use gNFB, capacitor choice will make a bigger difference.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.