[bearFNF]

I've had my L300 for close to a week now and only today I noticed a little popping sound on both sides when turning the SRM-252S energizer off. Is this to be expected? For context, I'm using a Jameco 12v power adapter with a reverse polarity plug, if it helps.

Thanks!

Do you turn the volume down all the way when you turn the amp on or off? Might help reduce the pop??

 

[Tarkus1984]

Do you turn the volume down all the way when you turn the amp on or off? Might help reduce the pop??

For the 252S, the only way to turn the device off is to turn the volume all the way down. Likewise, turning it on requires to turn the volume knob up. It doesn't have a separate on/off switch. Thanks for the suggestion!

 

[penartur]

I have a weird problem with imbalance, seems to be a bit different from what other people experience.

So I've purchased used Stax SR-5 with SRD-6/SB adaptor, and when I first plugged everything in, the left speaker was like 10x quieter than the right one. By that time, both headphones and adaptor spent around a month or two in the box, disconnected from everything. Seller claims that they are unaware of previous user having any problems.
The problem is definitely not in the source; I tried connecting both channels of SRD-6/SB to the same channel on the amp (for the mono sound), and the problem persisted.
I've tried non-invasive methods that I've found in this (and previous) threads: to unplug headphones and touch all six pins with the finger at the same time, to slap the quieter speaker with a hand to help membrane to unstuck. Tried this multiple times, to no effect. Letting headphones play music for two weeks helped somewhat: the left speaker became only 1.5x quieter than the right one.
And then the weirdest thing happened, after I left them for two days connected but not playing anything, I found them with no noticeable imbalance at all. However, after an hour of usage, the imbalance returned: the left speaker again became 1.5x quieter than the right one, and persisted for the rest of the day.
After another two-day break, I again found them balanced, and the imbalance again returned after an hour of usage.
Does anybody here have any idea what could be the problem, and whether there are any non-invasive ways to try to solve it?

 

[timb5881]

I have a weird problem with imbalance, seems to be a bit different from what other people experience.

So I've purchased used Stax SR-5 with SRD-6/SB adaptor, and when I first plugged everything in, the left speaker was like 10x quieter than the right one. By that time, both headphones and adaptor spent around a month or two in the box, disconnected from everything. Seller claims that they are unaware of previous user having any problems.
The problem is definitely not in the source; I tried connecting both channels of SRD-6/SB to the same channel on the amp (for the mono sound), and the problem persisted.
I've tried non-invasive methods that I've found in this (and previous) threads: to unplug headphones and touch all six pins with the finger at the same time, to slap the quieter speaker with a hand to help membrane to unstuck. Tried this multiple times, to no effect. Letting headphones play music for two weeks helped somewhat: the left speaker became only 1.5x quieter than the right one.
And then the weirdest thing happened, after I left them for two days connected but not playing anything, I found them with no noticeable imbalance at all. However, after an hour of usage, the imbalance returned: the left speaker again became 1.5x quieter than the right one, and persisted for the rest of the day.
After another two-day break, I again found them balanced, and the imbalance again returned after an hour of usage.
Does anybody here have any idea what could be the problem, and whether there are any non-invasive ways to try to solve it?

It may be the self bias on SRD-6, Try running them continuously with music playing to see if they hold balance after 24-48 hours. You could have a cold solder joint in the cables or adapter.

 

[penartur]

It may be the self bias on SRD-6, Try running them continuously with music playing to see if they hold balance after 24-48 hours. You could have a cold solder joint in the cables or adapter.

Left them playing music for 18 hours, the imbalance is still around 1.5x.

 

[SHAMuuu]

As a fan of the vintage estas I've also encountered the quirks of balance issues. Sr5/sigma nb

Luckily using receiver with L/R and Energizer can be last resort.

But when a channel cuts out I've unplugged the aux line and plugged back in while it's active. TAKE OFF HEAD WHEN DOING THIS. it makes loud squeal but for me 90% of time it will reawaken the dead side or bring balance back. Sometimes I need to repeat.

This happens when I leave them sitting for a month or two and not using often.

Reawakened like Phoenix from the ashes.

 

[bearFNF]

Left them playing music for 18 hours, the imbalance is still around 1.5x.

If you can find another energizer or amp to try the earspeakers on it might tell you if it is the earspeakers of the SRD6 that is the root issue. (or both.....)

 

[penartur]

I've unplugged the aux line and plugged back in while it's active.

Do you mean, unplugged the stax adaptor from the ordinary amp?

 

[SHAMuuu]

Do you mean, unplugged the stax adaptor from the ordinary amp?

No. The aux in my case is RCA cable. Which connects to the receiver. I use srd6/7 with vintage energizers. So connection between dac and receiver is the aux cable.

Eg. I use sdac to JVC vintage receiver which connects to Energizer. So basically I disconnect at the dac the audio signal.

Works for me.

 

[Phishin Phool]

So I finally got around to EQ'ing my L300 with blue tack mod and I must say that my other headphones are going to be quite lonely. I may occasionally use my Fostex TH900 (Lawton mod and custom wood cups) paired with my Wii Audio amp as I really enjoy that combo for bass heavy music but my Koss Electrostats and Beyerdynamic DT990's are going to gather dust. MY Bowers and Wilkins P7 wireless are my mobile cans with my phone so they will stay in rotation but they are not as good as my listening station cans.

 

[alota]

An advice, please. My first and only contact with stax was many years ago with 009. Now i won on ebay the srm-1 mk2, so i'm thinking to start with electrostatic. The amplifier has many years. Someone knows in E.U. somebody for a good revision of the amplifier? I know Birgir from mjolnir-audio but he is located in Iceland. Thank you

 

[SolarCetacean]

A CCS-modded SRM-006tS that I bought from Spritzer arrived today to replace one of his modded SRM-006tA amps that I bought in 2021 but failed in a headphone meet a few months ago. Sound-wise, I can't compare them, because the A has a bad left channel (L+ offset stuck at +350V and left channel tube red-plates) that will damage headphones and tubes and I haven't listened to them in over 2 months, but I expect them to sound very much the same; they're basically the same circuit with the same mod performed on them. The new S has an upgraded transformer that Spritzer installed which looks pretty slick and might behave better when the amp is stressed. The potentiometer's volume scaling could be different too, as I used to put the volume at 2/10 on the A, but now I only need to put it at 1.5/10 while my listening volume and input level haven't changed. Compared to my SRM-D10, both of the modded 006t units have tighter, less bloomy bass, more detail, and clearer treble.

On to non-sound differences. The input indication LEDs are now red on the S instead of green. It gives the amp a more aggressive look. The main section of the volume knob is now a darker grey compared to the silver of the smaller front section for L adjustment. On the A, both sections were silver. Knob feel is comparable. The one letdown on the S is the power button feel. It's too springy, needs more force to push in, and is a bit squeaky when turning it off. In contrast, the old A's power button made a very solid "ca-CHUNK" sound when I turned it off, which made me feel like I was operating real machinery, so it's a rather poor showing for the S in that regard. Not sure if it's just an age thing (although this unit is new enough to be originally a 100V-only unit, which is why Spritzer replaced the transformer), or if all the S units have this weak-sauce power button.

Does anyone know where the buzzing noise comes from in these amps? After the tube warm-up period and the amp fully powers on, this moderately pitched buzzing noise starts and continues until I turn off the amp. This occurred with both the A and the S and occurs even without any inputs connected.

I have 2 matched NOS RCA Clear Top 6CG7 tubes that were originally bought to repair the old A amp (there turned out to be more wrong than just a blown tube) that I might try to install down the line.

 

[KDS315]

An advice, please. My first and only contact with stax was many years ago with 009. Now i won on ebay the srm-1 mk2, so i'm thinking to start with electrostatic. The amplifier has many years. Someone knows in E.U. somebody for a good revision of the amplifier? I know Birgir from mjolnir-audio but he is located in Iceland. Thank you

Stritt Audio in Freiburg, Germany

 

[Sandro Sena]

The more I read comparative reviews of the Stax and electrostatics in general, the more I am shocked at how underrated the SR-009 model is, and this reflects its current price on the used market (generally the same price or even cheaper than an SR-007 MK1/MK2, for example). I ask your permission to assume the cretinous role of prophet: one day, when the ethereal, diaphanous, dreamlike nature of the Stax so exquisitely represented in this model is completely eliminated, so that they all sound "earthy" and "heavy", that is, when they sound like anything else built with any other technology, then the immaterial ghost SR-009 will come back to haunt us... costing 8k, of course.

...................

I recently had the X9000 in my home, a pleasure provided by a friend.

The inevitable question I asked myself: is this really a Stax? It seemed to me that Stax has produced a model for those who don't really like the electrostatic sound.

 

[kid vic]

Hey Stax gurus,

Just wondering if anyone has tried to do this mod to a Stax SRD-4 Electret transformer. I'm curious if its possible as I would like to get/make a better alternative to the ESP-950 box at a low price and SRD-4s are quiet common at low prices.