[jgazal]

Hello everybody!

I am not having my best financial time right now and importation taxes in Brazil are really high (prohibitive 60% including price and freight) so I was wondering if Stax affordable headphones like SR-303 would be a good choice to be amplified with a DIY amplifier.

I was also imagining why to spend much more than this if these people here (HEAD acoustics - NVH Division - Playback Systems - Power Amplifier for Electrostatic Headphones PVA IV.3 - Recommended components) are working with SR-303 to make noise professional Sound analysis and optimization and Vibration measurement technology...

Shouldn’t SR-303 be as precise as O2 mk2?

I know people will tell me that O2 mk2 sound different, have real leather, top quality structure etc, but does it sound more real than SR-303 when listening to acoustic recordings with lots of ambience and no need of “bass slam”?

Thanks in advance.

Jose Luis

 

[The Monkey]

You're working too hard to convince yourself of something. The SR-303 are great phones for the money. Hell, they're great period in my opinion. No, I don't think they're as good or as precise as the O2 mk2, but so what. You still get a lot for a lot less.

Now tell us more about this DIY amplifier...

 

[jgazal]

There is nothing special about the amplifier.

My intention is to go after some straightforward design from John Broskie at Tube Cad Journal (The Tube CAD Journal, Electrostatic Headphones and The Tube CAD Journal, Electrostatic Headphones Amps -Part 2-) with a little help from someone who had already built a tube amplifier.

I would not make more than that because I am not electric engineer…

Thanks,

Jose Luis

 

[The Monkey]

I, for one, would be interested in how it turns out. Please keep us posted.

 

[HeadphoneAddict]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif What? That makes no sense Larry and it should be no problem to modify. Most SB's have a third transformer which steps up the voltage off the audio transformer even higher but all of the Stax bias supplies are limited to a 100v input so a Pro or a normal bias unit makes no difference. It's also easy to grab a drill and add a small hole to fit a power cable.

I could have sworn that's what audiocats told me - my modded SRD-7SB takes longer to charge pro-bias phones than my SRD-7 Mk2 does. I guess I could be wrong.

 

[spritzer]

Quote:

Originally Posted by jgazal /img/forum/go_quote.gif There is nothing special about the amplifier. My intention is to go after some straightforward design from John Broskie at Tube Cad Journal (The Tube CAD Journal, Electrostatic Headphones and The Tube CAD Journal, Electrostatic Headphones Amps -Part 2-) with a little help from someone who had already built a tube amplifier. I would not make more than that because I am not electric engineer… Thanks, Jose Luis

It's a good basic design but you can certainly do better then that for not much more money. I've just started testing my own version of this amp and it is very promising, but it uses far better tubes then the 6CG7/6SN7. They have no place in electrostatic amps (at least as output tubes) given their limited voltage handling.

As for the SR-303, it isn't a bad headphone but the midrange honk makes them worthless to me. The SR-007 Mk2 has the same problem though...

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif I could have sworn that's what audiocats told me - my modded SRD-7SB takes longer to charge pro-bias phones than my SRD-7 Mk2 does. I guess I could be wrong.

There should be no reason for this to happen. Both bias supplies use the same input voltage and the current here is very low, a couple of uA's so that's not a problem. I have no knowledge of what mods were done to your adapter but putting in a different Stax bias supply shouldn't have that effect.

 

[HeadphoneAddict]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif There should be no reason for this to happen. Both bias supplies use the same input voltage and the current here is very low, a couple of uA's so that's not a problem. I have no knowledge of what mods were done to your adapter but putting in a different Stax bias supply shouldn't have that effect.

Hmmm... It does take several minutes for the SB caps to charge up and completely charge a pro-bias phone.

 

[Keithpgdrb]

question for the stax Gods, and/or mafia... which doesn't exist..

Background: I am running, stax sr-lambdas >srd7-sb>Yamaha 2020 integrated amp>Phillips SACD 1000 or Pioneer PL-50 turntable with a denon 110 cart. it has taken some time, but I believe I have built up some nice components here.

situation: I went with acquiring a vintage stax system, because from what I read, it had all that I wanted. I purposely got the original lambdas because they are reported as being the most balanced. When I got the energizer and cans, I was running them through some pretty inferior equipment and sources. I noticed an upper midrange "peak" that was not pleasing. it sits of course, in the high range for men, and the low/strong area for women. these two areas, I love. I am now running much better equipment, with similar result.

Question: my question is this.. with what I am running, the peak is pretty strong, and a bit piercing at times. is there something I can do to mellow this? everything else about the sound is quite nice. am I running too much solid state equipment to get the warmth that I want? do I need to have tubes? This process has surprised me, as I really thought running everything through the yamaha would fix the balance. I await with bated breath, your suggestions.

 

[leaf]

Quote:

Originally Posted by Keithpgdrb /img/forum/go_quote.gif I am now running much better equipment, with similar result. Question: my question is this.. with what I am running, the peak is pretty strong, and a bit piercing at times. is there something I can do to mellow this? everything else about the sound is quite nice. am I running too much solid state equipment to get the warmth that I want? do I need to have tubes? This process has surprised me, as I really thought running everything through the yamaha would fix the balance. I await with bated breath, your suggestions.

Perhaps you could elaborate on "much better equipment" for a fuller equipment picture.

 

[Keithpgdrb]

Quote:

Originally Posted by leaf /img/forum/go_quote.gif Perhaps you could elaborate on "much better equipment" for a fuller equipment picture.

I'll snap some pics later if you wish, but I figured the equipment list would suffice. Regardless of my old vs new equipment, I am still experiencing the upper mid peak. I guess I am also asking if anyone else has found this peak to exist, and what setup has helped the issue.

 

[FrankCooter]

I'm the builder of the big DIY transmitting tube electrostatic amp that was exhibited at CanJam. Earlier in this thread there was speculation that this amp would cost $15,000. The actual construction costs were about $1,500. About $300.00 of that was in the fancy chassis materials. As much as possible, this amp was built with common "off the shelf", used,recycled, or surplus components. The sole exception being the custom Electra-Print output transformers, which ran about $350.00 for the pair. I could never afford the $5k for a top ranked electrostatic amp. This isn't a $5k amp, but it's not embarressed by one either. I'd like to encourage other DIYers to "push the envelope", and would be happy to answer questions or discuss the design. I've had a lot of positive comments. Thanks to all. It's very encouraging. The final design of this amp is still in flux. There is also a much more "sane" kt88 based little brother in progress. When the design is finished and proven, I'll post it in the DIY forum.

 

[The Monkey]

You, sir, rock. I've heard only awesome things about your amps.

 

[IPodPJ]

The pics on here don't do it justice. It was just stunning in real life. The few times I went over to it there was no one there and I didn't want to mess with it but I sure wanted to hear it.

 

[vcoheda]

Quote:

Originally Posted by FrankCooter /img/forum/go_quote.gif I'd like to encourage other DIYers to "push the envelope", and would be happy to answer questions or discuss the design.

i think you have already done that. i heard that your dynamic amp - the one with separate power units for each channel - was beyond outstanding.

what is the rough cost of that one?

this is the one.

 

[edstrelow]

Quote:

Originally Posted by Keithpgdrb /img/forum/go_quote.gif question for the stax Gods, and/or mafia... which doesn't exist.. Background: I am running, stax sr-lambdas >srd7-sb>Yamaha 2020 integrated amp>Phillips SACD 1000 or Pioneer PL-50 turntable with a denon 110 cart. it has taken some time, but I believe I have built up some nice components here. situation: I went with acquiring a vintage stax system, because from what I read, it had all that I wanted. I purposely got the original lambdas because they are reported as being the most balanced. When I got the energizer and cans, I was running them through some pretty inferior equipment and sources. I noticed an upper midrange "peak" that was not pleasing. it sits of course, in the high range for men, and the low/strong area for women. these two areas, I love. I am now running much better equipment, with similar result. Question: my question is this.. with what I am running, the peak is pretty strong, and a bit piercing at times. is there something I can do to mellow this? everything else about the sound is quite nice. am I running too much solid state equipment to get the warmth that I want? do I need to have tubes? This process has surprised me, as I really thought running everything through the yamaha would fix the balance. I await with bated breath, your suggestions.

Try Silclear on the phone pins. Actually put it on all contacts, plugs,IC's etc. It will boost the bass and generally smooth out the sound. It's about $30.00 for a lifetime supply from Mapleshade. This stuff really works for me. Send me a pm and an SSA envelope and I'll shoot you a sample.