Feb 25, 2023 at 1:59 PM Post #3,316 of 3,352
Apr 20, 2023 at 2:14 PM Post #3,318 of 3,352
For anyone interested, there is a thread going on about Topping EHA5 electrostatic headphone amp that is $400. It was released last week and a few head-fi people have received them.
 
Dec 21, 2023 at 2:46 PM Post #3,319 of 3,352
I got my first Stax amp in yesterday. I am debating getting an SRD-7 or a WooWee and then an amp with XLR inputs to compare and contrast. I don't know the difference between the WooWee or the SRD-7, like why would you prefer one vs the other besides cost?
 
Dec 21, 2023 at 6:42 PM Post #3,320 of 3,352
I got my first Stax amp in yesterday. I am debating getting an SRD-7 or a WooWee and then an amp with XLR inputs to compare and contrast. I don't know the difference between the WooWee or the SRD-7, like why would you prefer one vs the other besides cost?
I can't answer the question for you but if you are interested I do have an SRD-7 that I was thinking of selling if you wanted to pm me an offer as I was thinking of getting a different energizer.
 
Dec 23, 2023 at 11:01 AM Post #3,322 of 3,352
Don't know about current Woo Wee but in the past, apparently Woo had some issues about not having the appropriate safety resistors in the circuit, so I would go with the Stax.
Apparently that was only with the model that supported normal bias Stax, not the "pro" version that only supports modern ones. Tons of contradictory info online. Someone said The current Wee "Pro" had better modern transformers then the Stax, which is decades old at this point.
 
Aug 28, 2024 at 12:03 PM Post #3,323 of 3,352
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Dec 13, 2024 at 11:02 AM Post #3,324 of 3,352
Wow, this thread has legs! It’s 2024 and there is still a wee bit of activity in the thread.
Have a Merry Christmas and a Happy New Year, folks!
Chris
 
Dec 14, 2024 at 11:28 PM Post #3,325 of 3,352
FWIW I decided to "retire" my SRM-252 and pair My L300 and Koss ESP 95x with a Topping EH5A. Just received it a dya ago and so far very pleased better soundstage and bass / sub-bass IMHO.
 
Feb 6, 2025 at 10:26 PM Post #3,326 of 3,352
Oh hi.

I feel like entry level should be <$200. Pursuant to that i am developing a board that should be able to upgrade an SRD-4, 5, 6, or 7 to modern bias specs, including pro bias.

Anybody interested?
 
Feb 7, 2025 at 4:10 PM Post #3,327 of 3,352
Oh hi.

I feel like entry level should be <$200. Pursuant to that i am developing a board that should be able to upgrade an SRD-4, 5, 6, or 7 to modern bias specs, including pro bias.

Anybody interested?
Intriguing. What other upgrades would your board provide over stock?

Ive a (modded) SRD7mk2 already but I wanted to compare to an energizer so I purchased a 252s from Japan. Can anyone recommend a USA compatible power supply at least 4W, 12VDC, regulated, linear, 2.1x5.5mm plug, and center negative (reference)?

Edit: I searched more and saw this wall-wart recommended but have to use a polarity inverter such as this. Anyone can confirm?
 
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Feb 8, 2025 at 2:02 AM Post #3,328 of 3,352
Intriguing. What other upgrades would your board provide over stock?

Ive a (modded) SRD7mk2 already but I wanted to compare to an energizer so I purchased a 252s from Japan. Can anyone recommend a USA compatible power supply at least 4W, 12VDC, regulated, linear, 2.1x5.5mm plug, and center negative (reference)?

Edit: I searched more and saw this wall-wart recommended but have to use a polarity inverter such as this. Anyone can confirm?

Jameco's linear regulated supplies have a good reputation.

For energizers, aside from adding pro bias, it seems to be widely held that the ballast resistors on the bias lines should be 4.7M where some have them at 2.2M. That the 0.01uf cap between the bias voltage and center tap on the transformers should be omitted. That if you can remember to be careful with the volume knob, the polyfuse type PTC devices padding the transformers may be swapped out for 4.7R resistors. Some of them lack 27-ohm resistors across the transformer primaries and some people feel like they should be there. Also, the SRD-7 Pro and MkII have some MOVs across the outputs for protection, which you could optionally install or not.

I'm at a stage where i should print out the board image and visually check how well the mounting works in the SRDs i have. The 5 and 7 have the mounting holes 90mm apart where the 4 has them 50mm apart, so there will be two sets of mounting holes. What I'm not sure about is fitment in the 6, which also seems to have them 90mm apart but is as small as a 4, so there is less wiggle room than in a 7.
 
Feb 8, 2025 at 9:21 PM Post #3,329 of 3,352
Sounds very interesting, I will love to hear how this pans out.
 
Feb 22, 2025 at 2:51 PM Post #3,330 of 3,352
IMG_6014.jpeg

Stax SR-207 first impressions w/ SRD7:
- Smooth detailed treble (classic Stax).
- Some vocal or mid forwardness that is an immediate possible deal breaker (classic Lambda peak).
- Not disappointed because this sound was expected and I plan to address with modifications or otherwise EQ.
- I so much prefer the non-L headband and build quality.

I did try with 252s amp as well but dont think I noticed a difference. I tried measuring a difference but its too difficult to get very consistent measurements with the poor seal of the shallow Lambda pads so will try again after I padroll… For now I will try comparing measurements of SRD7 vs 252s using my modded SR-X1. (to be continued)

fyi, I am using an uprated power supply with 252s. Some say it makes a difference but Ive no idea.
 
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