audio-talk

to resurrect this thread .... I've been listening to the amp for some time now, and have a really annoying issue i can't trace,,, i have a rustling/crackling noise mostly from the RH channel, I've swapped valves around, and even replaced the EH 6SN7's with US built ones, but to no avail.. looking ca...

i'm after a 6sn7 to upgrade EH russian valve in there presently.
not after anything mega expensive.
maybe you've got a single valve spare somewhere ?
might also consider a pair of 5687 as well
thanks
george

after some googling it seems that its not so uncommon for 5u4gb's to rattle. i also noticed that the tx secondary is 100 ohms, this might be a bit low? i found the min resistance for 5u4 (non gb) is 170r. current rectifier is EH, options are, add series resistors, 39r to each anode, or new rectifier...

i powered up the kit1 tonight, all seems ok, voltages all near enough. only problem is a rattling/rustling/tinkling from the rectifier itself. it's the same sound as light bulbs sometimes make when they are on their way out. should i be concerned? it's audible from near the amp but i'd describe it a...

ok, thanks, this is for the input tubes, (6.3v) but still only 0.4w, i'll throw them in, i was just hoping to avoid a few more components, schematic here for easy ref. http://www.4tubes.com/SCHEMATICS/BY-BRAND/Audio-Note/Kit1/kit1-psu.gif http://www.audiofil.net/data/upload/20090315_102640_kit1-audi...

yes- -i should use the 100r resistors as a virtual center point?
or
yes- - just connect one side of the heaters to the elevated voltage (or gnd on the other tube)

now the 300b amp is nearing completion, i'm thinking of the next project as always! i currently have a hybrid 'starving Student' amp using Ecc82 and FET class A buffer. the next one needs to: A) sound better than the SSHA, B) be all valve.. of course, C) driver most headphones including low impedanc...

for interest there are a couple of nice new drivers for line sources, one is 40mm chassis size, the other 59mm, http://www.tymphany.com/files/TC5FB00-08%20Preliminary%20spec%20sheet%20Rve1_0%20%20%2020121126.pdf http://www.tymphany.com/files/TA6FC00-04%20Spec%20Sheet%20Rev%203_0%202013-1-14.pdf i'd ...

pushing on with the build, hopefully complete next week, a few more questions, there is a strange arrangement in the PSU, the outputs for 395 and 375v are from the main B+ via dropping resistors and caps, but the final smoothing cap does not have it's -ve terminal returned to the star earth on the P...

I've probably missed this somewhere, but which pre amp are you running to get the balanced outs?

exactly...
just wondering if i should used screened cable to go from driver pcb to 300b grids,

time for an update, work on the amp has been sporadic, too much going on at work at the moment, anyway see some progress pictures below. upgraded copper binding posts, http://gallery.seloc.org/albums/userpics/27715/terminals.jpg assembled boards in place http://gallery.seloc.org/albums/userpics/2771...

OPA627 perhaps? it's quite good, also consider the Nelson Pass B1 buffer, ridiculously simple, and excellent, i'm using the more complicated DCB1 version with discrete shunt regs and no coupling caps, sounds amazing! circuit below, actually it's not exactly the circuit, but Pass's own schematic comp...

as per title,
looking for a pair of 5687 or equiv.
prefer modest, sensible priced over high cost fancy options.

thanks

as per title, i'ff off to the USA for a few days, i'm thinking of bringing back some audio goodies, typically i can't think of any of those cheap online shops in the US.... so what should i bring back.... i'm thinking of getting a rasberry Pi to turn into a squeezebox thingy. also i'm looking for so...