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SOHA II Builders Thread - Page 66

post #976 of 1688
Quote:
Originally Posted by wiatrob View Post
I like the hex, the grommets will clean up the look - although you may need to vinyl due them like CFCubed did on his CTH - Chris, do you have a link to that process?
My vinyl dye link is in the Post Pics thread, could search my posts there for it but think its overkill for 2 little tube grommets... Vinyl dye is not cheap & not so available. I think the usu spray he used on the grid would work well enough for them, or could leave 'em black (ala the 1/2" jack).
post #977 of 1688
Is it possible to use SOHA II as a power amplifier to a pair of speakers, for example, those sensitive fostex full spectrum speakers. It looks the SOHA II has a few watt output capabilities.
post #978 of 1688
Thread Starter 
Unfortunately, the SOHA II doesn't have enough juice to make much power since its maximum current output is less than 100mA.

However, if you want a headphone amp that can also drive speakers, try the EHHA.

http://www.head-fi.org/forums/f6/cav...ne-amp-422429/

Cavalli Audio
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
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post #979 of 1688
thanks runeight.
Does a 2x18V transformer work for SOHA II?
post #980 of 1688
I'd leave them black. Too much silver IMO.

After a few days of listening to this amp, I've noticed a few things: But first a detail of the setup (which is definitely not 'audiophile' grade), PS3 source, HDMI to Panasonic Plasma, Acoustic Research RCA cable (10$ surplus special) and the piece de resistance: Signal Flex SF-140 32ohm?? closed headphones.

These headphones require an amp. I've tried them in un'amped sources and there's no bottom/high end. Complete bandpass filter sound. My CMOY drove them ok, nice mid/high end, not much low end again. The SOHA II through these headphones makes all my old and new music sound like I was listening to it for the first time again. Perfect tight bass, super wide soundstage, the highs sound liquid smooth. I had no idea these no name headphones sounded so good. A former, former roomate of 2 houses ago forgot these when he moved out and never came back for them. I can't find any info on these phones. But I'm pretty happy with them for the moment. I have to say that the DAC in the Panasonic Plasma is better than the DAC in my Sony MP3 Walkman. It sounds grating to me through the SOHA II, as do MP3's lower then 256kbit. Even still the compression artifacts are distracting, 128kbit makes me grind my teeth. Thanks Alex for a great amp!

Quote:
Originally Posted by cfcubed View Post
My vinyl dye link is in the Post Pics thread, could search my posts there for it but think its overkill for 2 little tube grommets... Vinyl dye is not cheap & not so available. I think the usu spray he used on the grid would work well enough for them, or could leave 'em black (ala the 1/2" jack).
post #981 of 1688
Congrats on your amp build jjazzyj Enjoy!
post #982 of 1688
Quote:
Originally Posted by jjazzyj View Post
I'd leave them black. Too much silver IMO.

After a few days of listening to this amp, I've noticed a few things: But first a detail of the setup (which is definitely not 'audiophile' grade), PS3 source, HDMI to Panasonic Plasma, Acoustic Research RCA cable (10$ surplus special) and the piece de resistance: Signal Flex SF-140 32ohm?? closed headphones.

These headphones require an amp. I've tried them in un'amped sources and there's no bottom/high end. Complete bandpass filter sound. My CMOY drove them ok, nice mid/high end, not much low end again. The SOHA II through these headphones makes all my old and new music sound like I was listening to it for the first time again. Perfect tight bass, super wide soundstage, the highs sound liquid smooth. I had no idea these no name headphones sounded so good. A former, former roomate of 2 houses ago forgot these when he moved out and never came back for them. I can't find any info on these phones. But I'm pretty happy with them for the moment. I have to say that the DAC in the Panasonic Plasma is better than the DAC in my Sony MP3 Walkman. It sounds grating to me through the SOHA II, as do MP3's lower then 256kbit. Even still the compression artifacts are distracting, 128kbit makes me grind my teeth. Thanks Alex for a great amp!
jjazzyj, what tubes are you using? The stock RCA 5963?
post #983 of 1688
Thread Starter 
Quote:
Originally Posted by jjazzyj View Post
I'd leave them black. Too much silver IMO.

After a few days of listening to this amp, I've noticed a few things: But first a detail of the setup (which is definitely not 'audiophile' grade), PS3 source, HDMI to Panasonic Plasma, Acoustic Research RCA cable (10$ surplus special) and the piece de resistance: Signal Flex SF-140 32ohm?? closed headphones.

These headphones require an amp. I've tried them in un'amped sources and there's no bottom/high end. Complete bandpass filter sound. My CMOY drove them ok, nice mid/high end, not much low end again. The SOHA II through these headphones makes all my old and new music sound like I was listening to it for the first time again. Perfect tight bass, super wide soundstage, the highs sound liquid smooth. I had no idea these no name headphones sounded so good. A former, former roomate of 2 houses ago forgot these when he moved out and never came back for them. I can't find any info on these phones. But I'm pretty happy with them for the moment. I have to say that the DAC in the Panasonic Plasma is better than the DAC in my Sony MP3 Walkman. It sounds grating to me through the SOHA II, as do MP3's lower then 256kbit. Even still the compression artifacts are distracting, 128kbit makes me grind my teeth. Thanks Alex for a great amp!
Happy to hear the good news!! Now you must listen to your entire music collection again.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
Reply
post #984 of 1688
The tubes I'm using are the GE 5963 grey plates that came with the Glass Jar kit. I've listened to this amp with a few different 'generic' headphones and they seem to colour the sound far more than the tubes do. Those Signal Flex headphones sound like how people describe the AKG K601. The bass is there but is isn't 'enhanced' by any stretch. As an example, when I'm listening to trance, some tracks have lots of bass, and others seem like there is no bass. It all depends on the track it seems. When I plug in my POS Sony 'DJ' headphones everything is a horrible blurry mess filled with boomy bass. They really are the worst headphones I've ever used. That includes the airline ones...

Quote:
Originally Posted by wolf18t View Post
jjazzyj, what tubes are you using? The stock RCA 5963?
post #985 of 1688
Haha, my CD binder which was collecting dust is now by my SOHA II!! I'm doing the ADD music surfing dance, listening to a few minutes of every song to hear the nuances and detail that I didn't hear before.

Quote:
Originally Posted by runeight View Post
Happy to hear the good news!! Now you must listen to your entire music collection again.
post #986 of 1688
Quote:
Originally Posted by jjazzyj View Post
The tubes I'm using are the GE 5963 grey plates that came with the Glass Jar kit.
I think I'll order and give RCA or GE 5963 a try. The ones (Phillips ECG 5963) that came in my kit sounded quite lifeless. Or maybe they just aren't made for RS-1.
post #987 of 1688
I found some NOS Sylvania/Philips ECG 5963 and some Sylvania 5814A locally for 3$ each and I'm giving them a listen right now. I realize this is probably more for the SOHA II tube thread, but it seems sort of dead. I'll let you know what I think.

Quote:
Originally Posted by wolf18t View Post
I think I'll order and give RCA or GE 5963 a try. The ones (Phillips ECG 5963) that came in my kit sounded quite lifeless. Or maybe they just aren't made for RS-1.
post #988 of 1688
Sylvania 5814A:

Much deeper bottom end at the sacrifice of tightness, more relaxed perhaps. More relaxed sound in general. Soundstage is interesting, music sounds more '3d'. Wish it had more high end detail.

GE 5963

Very airy and pronounced mid and highs, borderline annoying but still enjoyable, Wall of sound. Bass is subdued but tight. Not as '3d' as 5814A.

Need to combine aspects of both tubes.

Sylvania/Philips ECG 5963

One of the tubes seems microphonic. It's ok. Nothing special. Slightly more high end detail than 5814A though it might be my imagination.

Someone with better ears and better equipment than my Signal Flex SF-140 might have better commentary.

Quote:
Originally Posted by jjazzyj View Post
I found some NOS Sylvania/Philips ECG 5963 and some Sylvania 5814A locally for 3$ each and I'm giving them a listen right now. I realize this is probably more for the SOHA II tube thread, but it seems sort of dead. I'll let you know what I think.
post #989 of 1688
Here's another first time poster on this thread. Just finished my SOHA II, hot on the heels of an extended tweaking & development period with the Bijou.

The SOHA is very different from the Bijou, although IMO no less satisfying. Although significantly more complicated, it went together easily & following the excellent setup instructions, fired up without problems first time. All voltages & currents are as specified.

Using the GJ kit included JAN Sylvania 5963's, the sound is very tight & clean, with a good soundstage & 3D depth & air, but not to the same extent as the Bijou. I tried some Mullard CV4003's ("Box Plate", 1965) & these take it to the next level. Beautiful mids, especially female vocals (these tubes are famous for this) & a warmer more expansive sound than the 5963's. Highs are also a bit more extended. These old tubes with a classical "British" sound have softened the amp's sound, yet the beautiful deep tight bass is retained.

I'm running HD650's (with Stefan AudioArt cables) & the match is excellent, IMO. The SS output buffer better controls the bottom end of the 650's than the Bijou. Another great aspect of the design is the capacity to roll in many different tubes with very little effort required to dial them in. Many hours of harmless fun ahead here.

Other than a decent case/chassis (transformer & PCB are on two separate small chassis at present joined by a three core cable), the only other planned tweaks are upgrading some caps (C1, 2 & perhaps a few critical ones in the PS).

Hats off & many thanks to Alex for another cracker design.
post #990 of 1688
After an extended period of not using my SOHA II, I decided to clean up my input wires and go through the initial setup again today. All was well until I had to measure TPR and TPL vs. TB+R and TB+L. I tried three sets of tubes and not one set was even close to the 19 volt difference. I believe this indicates that my tubes are all no good?

When I was testing it, the epsilon tripped quite a few times. I have not tried to listen to it and hope that my problems will be solved simply by getting some new tubes. As a tube newbie, I believe I tried at least some of these tubes at 12.6 v, which they did not like and could have hurt the tubes.

Thanks for any and all help.
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