Latest Thread Images

Featured Sponsor Listings

the Pimeta-V2 thread

Oct 17, 2009 at 6:33 PM Post #92 of 652
Resistors are generic. There are many kinds you can use, they're available everywhere, and there's no big reason for me to recommend a particular kind. There are only two important rules for most of the resistors: use metal film types, and make sure they'll fit the 300 mil pin spacing. Other than that, use whatever is convenient for you, or which makes you happy.

Personally, I use Vishay-Dale RN55Ds, from Mouser.

EDIT: Some of the resistors have different pin spacing and some have wattage requirements, covered in the parts guide.
 
Oct 18, 2009 at 12:36 PM Post #93 of 652
Quote:

Originally Posted by tangent /img/forum/go_quote.gif
Resistors are generic. There are many kinds you can use, they're available everywhere, and there's no big reason for me to recommend a particular kind. There are only two important rules for most of the resistors: use metal film types, and make sure they'll fit the 300 mil pin spacing. Other than that, use whatever is convenient for you, or which makes you happy.

Personally, I use Vishay-Dale RN55Ds, from Mouser.

EDIT: Some of the resistors have different pin spacing and some have wattage requirements, covered in the parts guide.


Ok, thank you so much, sorry but I'm the biggest noob ever. I would like to have a balanced amp so, as you suggest in your guide, I'm going to use the scratchpad as fourth channel. How can I do that?
 
Oct 18, 2009 at 1:09 PM Post #94 of 652
Quote:

Originally Posted by acvtre /img/forum/go_quote.gif
Ok, thank you so much, sorry but I'm the biggest noob ever. I would like to have a balanced amp so, as you suggest in your guide, I'm going to use the scratchpad as fourth channel. How can I do that?


You'd better use two boards without ground channels.
 
Oct 18, 2009 at 1:23 PM Post #95 of 652
Quote:

Originally Posted by diditmyself /img/forum/go_quote.gif
You'd better use two boards without ground channels.


What does it mean? So, how would you use the scratchpad?
 
Oct 18, 2009 at 1:34 PM Post #96 of 652
The issue with trying to just add a fourth channel to the board is that the ground channel is not the same as the other two channels. You need four identical channels to do balanced. Using two boards would give you the four identical channels + two grounds.
 
Oct 18, 2009 at 1:38 PM Post #97 of 652
Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif
The issue with trying to just add a fourth channel to the board is that the ground channel is not the same as the other two channels. You need four identical channels to do balanced. Using two boards would give you the four identical channels + two grounds.


So how can i link two pimeta boards? How have you used the scratchpad?
 
Oct 18, 2009 at 1:43 PM Post #98 of 652
Quote:

Originally Posted by acvtre /img/forum/go_quote.gif
What does it mean? So, how would you use the scratchpad?


I'm not suggesting you should use the scratch pad at all. I mean, I don't think you can build a portable balanced pimeta because you need a 4 ch pot and some kind of "balanced" connectors, so size shouldn't be an issue. To my knowledge there are no portable balanced sources either. You need 4 channels. It must be easier to use the L/R channels of one board as L pos/neg and the other board as R pos/neg, than to cram in one more channel with all parts needed on the sctrachpad. I think there are some balanced old PIMETAs out there. Do some searching to see how they're made.
 
Oct 18, 2009 at 8:29 PM Post #100 of 652
Quote:

Originally Posted by acvtre /img/forum/go_quote.gif
Ok, thank you so much, sorry but I'm the biggest noob ever. I would like to have a balanced amp so, as you suggest in your guide, I'm going to use the scratchpad as fourth channel. How can I do that?


No one's worked out the details and posted it yet. Noobs don't make good pioneers.
smily_headphones1.gif


My advice is to build it with 3 channels now, enjoy it while the pioneers do their work, and then evaluate later whether to convert to four channels.

Quote:

Originally Posted by cobaltmute
the ground channel is not the same as the other two channels


True, but off the top of my head, the biggest problem is just the lack of gain in the ground channel. This means either you configure all channels for G=1 -- getting G=2 due to the balanced action -- or just solder-tack an R3G into the ground channel if you really must have G > 1.

This from someone who has never built a balanced amp. Find salt grains. Apply appropriately.
 
Nov 6, 2009 at 11:03 PM Post #101 of 652
Hi guys, since I'm a noob do you have a set of resistors do suggest? I mean something that surely works good, how much bias, gain etc etc. I need only them in order to put the word end to the work.
 
Nov 28, 2009 at 11:05 AM Post #105 of 652
If you are using a RK27 pot simply connect a wire from one of the terminals on the switch to one of the "S1" pads on the circuit board.
Then connect another wire from the other switch terminal to the other "S1" pad on the circuit board (It doesn't matter which switch terminal is wired to which pad with a SPST switch (nobody is going to call a wambulance if you install your switch upside down)).
If you are using a RK097 pot you won't need to wire in a switch...
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 3 (members: 0, guests: 3)
Back
Top