[willisv]

I have been using 8416's for a while now and I really like them but I can't compare them to 6N1P's because I haven't tried them yet. I plan on doing Regal's mod in the near future then I will give them a shot.

 

[luvdunhill]

slightly related to this thread...

I heard a DIY preamp this past weekend that used a single 6N1P-EV tube. The builder says that he has acquired around 100 of these and has 6 that are of older, slightly different construction. I'm not all that familiar with this tube, but these seemed to have smooth black plates. Sound was starkly different when we compared the 2 tubes. Perhaps something for you guys to be on the lookout for.

 

[miky]

I currently have AKG K701 /62ohm and Rubycon photo flash 410uF caps (C5) bypassed by some Vitamin Q in parallel with K72P-6 (C6). I'm thinking about adding 70uF Obbligato Film Oil caps. What you say about this?

 

[JamesL]

Quote:

Originally Posted by miky /img/forum/go_quote.gif I currently have AKG K701 /62ohm and Rubycon photo flash 410uF caps (C5) bypassed by some Vitamin Q in parallel with K72P-6 (C6). I'm thinking about adding 70uF Obbligato Film Oil caps. What you say about this?

I hope you know how big those are..

 

[willisv]

Quote:

Originally Posted by miky /img/forum/go_quote.gif I currently have AKG K701 /62ohm and Rubycon photo flash 410uF caps (C5) bypassed by some Vitamin Q in parallel with K72P-6 (C6). I'm thinking about adding 70uF Obbligato Film Oil caps. What you say about this?

The only way to know is to give it a try and see how it sounds. I bypassed C5 in my Bijou with 1uF Mundorf silver/oils and they really improved the sound of my Bijou, although they are a little pricey.

Has anyone tried the AKG k240 sextetts with their Bijou yet? I just acquired a set and I would strongly recommend them to anyone with a Bijou, they sound so good with this amp!

 

[chobint]

Quote:

Originally Posted by miky /img/forum/go_quote.gif I currently have AKG K701 /62ohm and Rubycon photo flash 410uF caps (C5) bypassed by some Vitamin Q in parallel with K72P-6 (C6). I'm thinking about adding 70uF Obbligato Film Oil caps. What you say about this?

I can't comment on obbligato, but I'm using a similar combo. 410uf Rubycon photo, 70uf Dayton poly cap, and 1uf mundorf bypass. I've been happy with the changes.

to give an idea of size...

 

[fishski13]

wired up the PS mod. no love...no EZ81 glow. nothing went up in smoke though.

i have both transformers wired to the IEC inlet, tied in together on the L and N poles, but only one transformer is connected to the single PS i tried the mod on. the second unused transformer is not connected to the second PS board, with business ends taped/encapsulated. i still haven't finished the soldering on the second PS board, but wanted to try powering up one PS board.

i get continuity between the 2 primaries (black/blue and white/brown) with a resistance of 3.5 ohms. is this normal?

i get 0 volts across any of the secondaries.

i had no probs the first time around, but i wire in a second transformer, unloaded, and i get zilch.

i'm also employing Amphead's PS mods.

here's an aerial view...btw, i have a new respect for people who do P2P. my first time out was quite the challenge.

[/IMG]

 

[adamus]

not sue it read that right, but are you saying the tranformer unloaded is not producing any voltage on the secondaries?

 

[fishski13]

sorry about the confusion guys.

the "operational" transformer was not producing anything when connected to the PS board.

the second transformer is not hooked up to the PS board - just the primaries to the IEC inlet. but wait...

i disconnected the second transformer, powered up with only one transformer/PS board - no blown fuse, working fine, and getting 250V on the PS output. i did not have the amp boards connected when blowing fuses, and have not connected them yet. i'm just testing the PS mods. at least my P2P is holding up.

disconnecting the second transformer from the IEC is the only change i performed and all is working well.

when the fuses fried, this was immediately on power up.

do i need a higher rated fuse?

can anyone explain why i was blowing fuses before?

both of the transformers are 370 DAZ (DAX). i've triple checked the wiring on the transfos.

i will get the second PS board mod done this evening, and hope to have both of the PS sorted.

thanks everyone!

@ Amphead: awesome!

 

[pabbi1]

Yes, Ron, double awesome - too bad the system restore wiped out the post.

 

[runeight]

Quote:

Originally Posted by fishski13 /img/forum/go_quote.gif sorry about the confusion guys. the "operational" transformer was not producing anything when connected to the PS board. the second transformer is not hooked up to the PS board - just the primaries to the IEC inlet. but wait... i disconnected the second transformer, powered up with only one transformer/PS board - no blown fuse, working fine, and getting 250V on the PS output. i did not have the amp boards connected when blowing fuses, and have not connected them yet. i'm just testing the PS mods. at least my P2P is holding up. disconnecting the second transformer from the IEC is the only change i performed and all is working well. when the fuses fried, this was immediately on power up. do i need a higher rated fuse? can anyone explain why i was blowing fuses before? both of the transformers are 370 DAZ (DAX). i've triple checked the wiring on the transfos. i will get the second PS board mod done this evening, and hope to have both of the PS sorted. thanks everyone! @ Amphead: awesome!

First, let me understand what's happening. You've isolated the new PS with the TIP50 cap multipliers?? And you get 250V from the reg?

If so, then what happens when you connect this PS to the amp boards and power up? If power up is successful, what is the voltage at the R7 point on the new board. And, we'll need to add one more jumper from the new board to the old board. Later.

 

[fishski13]

Quote:

Originally Posted by runeight /img/forum/go_quote.gif First, let me understand what's happening. You've isolated the new PS with the TIP50 cap multipliers?? And you get 250V from the reg? If so, then what happens when you connect this PS to the amp boards and power up? If power up is successful, what is the voltage at the R7 point on the new board. And, we'll need to add one more jumper from the new board to the old board. Later.

yes, TIP50 cap multipliers, one PS board, one transformer, 250V on the output with 100K resistor across to ground. both R7 and R8 are connected.

i need to duplicate this for the second PS board and transfo to power the second set of amp boards. what's with the new jumper - could you elaborate?

i will hook-up the amp boards later this evening after dinner and measure R7.

 

[amphead]

Pabbi here is your amp again. The white wires connect to the converter outside of the case.

 

[runeight]

Actually, looking at the board again I am wrong about the need for an additional jumper. Connecting the O/P of the cap multiplier board to R7 automatically connects this to R9. It was the R9 connection that I thought had been left out. My mistake.

Your new R7 voltage should be well above 250V giving the regulator plenty of operating room for the higher current load.

Your fuse could be blowing simply because with two amps/transformers you have doubled the inrush current into the primaries. I would test each transformer/PS/amps separately first. Make sure that each channel is working. Then rig up both trafos to the power with a larger fuse. This should work.

 

[pabbi1]

Even prettier the second time - so, what is the function of the converter board - your balanced source? inquiring minds wanna know... ? Pity my transformer cover isn't here yet from vt4c, but will be soon.

I really cannot wait to see how she sounds now that I have the SOHA II running. Shouldn't be too very long now...