Help for Building The S.E.X. 2.1,Impedance Switch and C4S

[i luvmusic 2]

I used the Mundorf Silver/Oil in mine and found them a very nice improvement over the Solens, specifically better high end and low end extension which were a little rolled off with the stock caps. I chose the Silver/Oil on the basis of many caps roundup reviews i read all pegged them as being the most neutral sounding of the Mundorf range. The fact i haven't changed a thing with the amp since then really speaks to how happy i am with them.  I do have a pair of Jupiter flat stacked wax caps to try at some stage too, they popped up on eBay at a price i couldn't resist 

http://bottlehead.com/smf/index.php?topic=5316.msg53501#msg53501

Loquah installed the Silver/Gold/Oil versions into his which are known for being warmer in the mid range, which coincidentally is exactly how he characterized them at the bottom of his post below.

https://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline#post_9831527

You did ask...

I was going to use the Mundorf 1.5uf 600V Supreme which is less expensive than what you have used but now i changed my mind i might used something else too many caps to chose from.


Thanks!

[mcandmar]

There really isn't a whole lot of options over 600v that dont break the bank.  There a bunch of different cap round up tests you should read through first before making up your mind, when you read 3-4 different reviews you will start to get a good idea of the flavor of each brand/model.

I bought a pair of these to try as i have used them before with good results, http://www.ebay.co.uk/itm/261593528750?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT, only problem is they are huge at 2" x 5".  I should have known really as all the Russian caps usually are.

[i luvmusic 2]

Need help for DEAD Left channel,tubes are ok  both tubes works on right channel.I saw a smoke,blown the fuse left side smells burnt.I replaced the fused and turned it back on both tubes lights up but left channel is dead.

[mcandmar]

Need help for DEAD Left channel,tubes are ok  both tubes works on right channel.I saw a smoke,blown the fuse left side smells burnt.I replaced the fused and turned it back on both tubes lights up but left channel is dead.

Resistance checks, if that doesn't find anything post a few pics.    I would hold off on powering up again until you trace the magic smoke.

[i luvmusic 2]

Resistance checks, if that doesn't find anything post a few pics.    I would hold off on powering up again until you trace the magic smoke.

Resistance check is all good but C4S board B LED's are dead.

[mcandmar]

The engineer in me is asking "what did you change last?"

If you visibly inspect all the resistors can you see any burnt or discolored?

[i luvmusic 2]

The engineer in me is asking "what did you change last?"

If you visibly inspect all the resistors can you see any burnt or discolored?

No discolored but i found the resistor connected to T16 and T20 is touching the 0.1uf cap lead connected to T19.The 0.1 caps are the last two capacitors that i replaced.C4S Board B side LED's are dead. 

[mcandmar]

What i think that did was connect the start of the power supply ~420v to the anode of the 1st tube stage, which would have shorted the output side of the C4S board to the B+.  I dont really know how much damage that would do to the C4S board, it may have zapped all of it

[i luvmusic 2]

I just double checked the resistance and all are with in spec just to make sure.Is there a way to test the C4S Board if it is functioning properly?

Thanks!

[mcandmar]

Not that i know of.  If your multimeter has a diode test function you could check the LED's, you should get no reading in one direction, and with the leads reversed you should get a voltage reading ~1.55v while it lights up.  If you get no reading in either direction they need replaced.

Transistors would probably need removed from the board to test them, and ideally a transistor tester to check them.

[i luvmusic 2]

It looks like the easiest solution is to replace the C4S.Before i order the  replacement board maybe i should disconnect the board and put back the resistor where it was to make sure the amp is functioning properly.I don't want anymore surprises.

[Paul Birkeland]

Maybe you could post your voltages?

[Natural Sound]

I used the Mundorf Silver/Oil in mine and found them a very nice improvement over the Solens, specifically better high end and low end extension which were a little rolled off with the stock caps. I chose the Silver/Oil on the basis of many caps roundup reviews i read all pegged them as being the most neutral sounding of the Mundorf range. The fact i haven't changed a thing with the amp since then really speaks to how happy i am with them. 

I'm still building my 2.1 but decided to leave the stock Solen parafeed cap alone and change the .1 interstage cap with a .1uf/630 volt Theta film and foil AudioCap from Parts Express. I took this advice from another Bottlehead, I think it was Cary. I spent the lions share of my "mad money" on pre-ordering a Bottlehead DAC. I might get something more exotic in the future. Or I may absolutely love the Solen/Theta combination. Time will tell I guess.

[i luvmusic 2]

Maybe you could post your voltages?

Sorry! for the late reply.
i have checked the RESISTANCE and VOLTAGE they are all good,The C4S board B side is  definitely DEAD/FRIED everything was discolored and smells burnt.I just ordered a new C4S kit from eileen few days ago.The amp is working fine without the C4S but i miss that sound with C4S hopefully i will received my new kit soon I can't wait. 
THANK YOU GUYS for all your HELP!
   

[i luvmusic 2]

 I need help the LEFT CHANNEL just died,By inserting the Headphone Jack halfway both channel will work if the jack is inserted all the way in only right channel works.
Thanks in advanced!

Here are my Voltage readings.
Terminal
1  220V
2  0
3  0
4  440V
5  220V
6,16  420V / -0.639
7,17  0
8,18  0
9,19  19.5V / -0.435
10,20  440V / 441V
11,21  402V / -0.695
12,22  0
13,23  0
14,24  0
15,25  17.60V / 1.2V
A1,B1  close to zero
A2,B2  396V / -0.702
A3,B3  17.60V / 1.2V
A4,B4  0 / -19
A5,B5  83V / -0.718
A6,B6  2.6V / 0.99
A7,B7  -2.8V / 2.8V
A8,B8  2.9 / 2.9V
C1  -3.26V
C2  3.08V
C3  0
C4  -3.30V
C5  3.30V