Stat amps on ebay

[spritzer]

Yup, the WES is for people who have no idea what quality sounds like and think "large chassis, toobz and high price" is a substitute for good engineering. 

I actually thought about buying one recently and document in a video just how to turn it into something useful for less than 1k$.  Hell you could do it for even less and keep the stock PSU...well probably regulate it as it is just balls...

[JimL]

20 hours ago, kunalraiker said:

I thought the amps were aiming different markets.

In terms of price, they are aimed at the same market.  In terms of quality, well....

 

If you do a search for electrostatic headphone amplifier schematics, both commercial and DIY, you'll find a lot of resistor loaded output stages, you'll find several constant current loaded output stages, and you'll find some transformer output stages, but you won't find any choke loaded output stages.  The Woo WES uses choke loaded output stages.  Now, there are two possible reasons why they are unique in this respect.  The first is, they have a patent and nobody else can use it - however choke loaded output stages have been around for a long time, so that's not it.  The second reason is, they don't know what they are doing and are using an expensive topology that is demonstrably inferior for this particular purpose.  See my thread on current requirements for electrostatic headphone output stages for infinite gory detail on why current loads are the optimum way of loading output stage active devices from a strictly engineering perspective.

 

Second, the WES has a passive power supply rather than a regulated power supply.  Now, Stax also use a passive power supply, however they are much cheaper and much smaller so there's a good engineering reason for that.  In an allegedly state-of-the-art design, there is no reason NOT to use a regulated power supply since the ideal power supply provides a perfectly stable, noiseless and unvarying voltage regardless of the demand on it, something no passive supply can do, and something a regulated supply is much closer to doing.

 

In other words, IMHO the WES is state-of-the-wallet, but not state-of-the-art.

Edited March 14, 2017 by JimL

[wink]

Or, perhaps, a state of the ego.......  

[JimL]

Wow!  A Stax SRM-T1S went for $810 and a T1W for $896 on ePay in the past week!

[purk]

3 hours ago, JimL said:

Wow!  A Stax SRM-T1S went for $810 and a T1W for $896 on ePay in the past week!

Must be a bidding war.    

[purk]

Not electrostatic amp but this is a complete steal here.

http://www.ebay.com/itm/HEADROOM-MAX-BALANCED-HEADPHONE-AMPLIFIER-Upgraded-50KAX4-Volume-Control-/142279338346

The RK50 by itself is $800 right?  I own the Balanced Home with Max Module and this amp is amazing at driving the HD800 and nearly as good as my ECP DSHA-0 prototype.  This is supposedly even better.  The seller had it on ebay with BIN for $3500 for like 3 months and I made an offer at $2500 and he rejected my offer.  Wish I could have bought it for that price.

Edited March 21, 2017 by purk

[DefQon]

Purk don't get too excited for something you miss-read.

I don't think that amplifier has an Alps RK50 (I would be genuinely interested how they fitted one in there when it is clearly too big due to where the PCB is), the 50KAX4 shows up as one of Alps motorised 4 gang 50kohm pot. 

The actual part numbers for the RK50 designates it as part of the RK501 series, RK50112A0004 and RK50114A0001 are the dual and quad gang part numbers.

 

[n_maher]

They certainly offered the RK50 as an upgrade - https://cdn.shopify.com/s/files/1/0362/2465/files/MaxBalancedAmpManual.pdf?3915 - so it's entirely possible that it had one in it.  

[purk]

Definitely an RK50, I did check with the guy and that was a typo buy the seller.  He did sell it for that price.