Headphone Amplification

I figured something this rare deserved a thread of its own. Let me introduce the Stax SRA-7S, integrated amp for earspeakers. This was introduced in 1966 for the SR-1 and remained in production into the 70's. With Stax we never really know when they stopped making something but given it's all tube design, it was dead by the mid 70's. This one was missing just one knob but amazingly they are still in current production. A full set has already been sourced... Those RCA's really need to go but pretty clean over all. Pretty much unmolested but somebody decided to remove the fuse holder. Not a good sign... Amp and phono stage on separ…

I have a two speaker system and I'd like to incorporate a STAX setup into it. I'd like to continue to use my preamps remote control, and I want to use my preamps XLR output vs. my Rec Out's because well, I'm just funny like that. Is there a preferred way to adjusting the two volume controls when using a preamp and STAX amplifier? I know the 717 & 727 have a volume bypass switch, but I'm trying to open up my options to what amp I eventually get. Thanks

There has been very tranparent and clear pictures of the 32000 USD base model of Warwick Aperio. Sonic wise, while it doesn't have the stage height of Hifiman Shang SR and maybe even the seperation of Stax X9000 driven by T2/ Grand Cayman with TOTL source, it does have the best low extension as well as the most normal shape of stage. While I feel TOTL AIO electrostactic systems as HE-1 and Aperio have better transducer and headphones (or most current after market electrostactic headphones are problematic here and there ), they might be limited by the geometery to accomodate the best amplification. Looking inside of the chasis, while I won't judge the component…

Here is something that has been cooking for a while but I've been just too busy to do anything about it. So JR Audio out of China have been building our amp designs for a while now and I started to hear horror stories almost immediately. They naturally have no right to use our designs and work in their crappy products but since when has that stopped anybody... I have been looking for one of these amps for a while now as I want to rip it apart and well... one owner contacted me. I'm going to ask him to come here and tell his story which is quite the tale. Let's just say Caveat emptor... So here is the amp and it arrived dead which will soon be clear. It is the K…

Removed due to wrong board post, please delete the thread

I was thinking of upgrading or supplementing my old Headsave Classic amp (3 x Burr-Brown OPA627, hooked up to an Arcam FMJ CD36 or Sony UHP-H1) with something new, not too expensive. I may still get a Chord Mojo 2, but this looks interesting at $219... just announced, with impressions coming out in a few days. The Schiit Midgard has a different discrete design, with a mixed-mode feedback and more power than the Magni+ I was looking at:

I'm doing a side gig reviewing headphones. Companies send me stuff and I give my opinion on things. I recently got a certain Moondrop Para planar which I thought sounded pretty okay. Then I saw the spec sheet and my hair stood up a bit- 101dB/V at 8 ohms. Or, when converted to actual efficiency figures... 80dB/mW. My question to the amp gurus here - will this load kill amps? It's a rare case of low efficiency combined with high sensitivity so people will be lulled into thinking that it's an easy load to drive. Like - hurr-durr, pot's only at 9'o clock and it's already hella loud! When in reality you're pushing serious mA and mW. And I'm not talking abo…

Hi all, I was advised by some head-fi members to inquire about the technical aspects of this amplifier here. Do let me know if I'm failing to follow any rules; just trying to avoid any catastrophes! Here are the photos of my amp: https://imgur.com/a/sshHA7B The amp is an 8FQ7 SRM-007t rated for 100v 50/60hz outlets. I have a step down transformer (PowerBright) rated for 120v to 100v, and my outlets are, I believe, 120v at 60hz (American). The transformer works fine with my Japanese SRM-252S, but the fuse has blown 3 times now when turning on the 007t (always the 2nd time it turns on; the first time seems to be working). I've tried debugging this for a bit, hence…

Well this just arrived and as is our fashion, it has not been plugged in at all before I rip it apart. I'm having some camera issues (bloody Lightroom) so not as many as I'd like. Now first off why this belongs on a trashpile... here is the output: It's a pain to get a camera to focus between the transformers so I ended up grabbing the phone. Those are the ballast resistors, two 1M units in series and one 3M3 unit, all in 1206 package so likely 150V rated. Yeah no... just no, this is not good enough!! It gets worse though... It's a shit angle but here is how the transformers connect to the output socket: Now do you notice any parts on this PCB e…

Found this on alibaba recently and it looks kinda interesting. They seem to have a fair number of internal pics and even an instruction manual (top right of the page) online so I figured I would post it here. I think this is the first energizer I have seen that requires manual bias adjustment when tube rolling/as matenance which is kinda interesting.

Hello, I dont have a great grasp of these topics so if I have some fairly base misunderstandings or bad assumptions let me know. Now onto the question. My understanding is that estats behave pretty predominantly as a capacitive load. If this is the case it would seem to me that a transconductance amp (that has not be rectified to voltage drive output/aka a 'current drive' amp) would be a fairly ideal way to run estats. Are there any amps that do this? is this how all estat amps do it and I am just not aware? If not, what are the reasons that we dont use an OTA output stage given basically all TOTL estat amps have a solid state output stage (only ex…

Where the hell should this thread go? Any thoughts on Schiit’s new “universal surround” dac/preamp/headphone amp? https://www.schiit.com/products/syn Some development history over on the other site (linked in announcement email).

It's an amplifier based on the stax t8000. I couldn't find the picture because the inside was not disclosed. It's an amplifier made by a famous Korean hi-fi amplifier maker and it weighs 60kg

This is my fist posting for this forum. I hope it’s to your liking ! Apart from the audio qualities, I am also interested in the technical qualities of equipment. So my posts sometimes will be a bit technical. Just skip the uninteresting bits. If that is almost all: so much the better. That way you have more time left for enjoying the music ;-) Quite recently I finally managed to obtain a Stax SRA-12S pre-amplifier with built-in ES headphone amplifier. According to the previous (first) owner the amp got very hot. Well, since it is supposed to run quite hot, I was not alarmed and bought the SRA-12S unseen (well…. just a photo). Unfortunately one channel of the …

I have a 2nd hand headamp aristaeus, the background noise follows the volume pot. I measured ac between L+/L- and R+/R-, the left is 3.48v when volume pot is turn to max while right is 1.74v, I swapped ecl84 and 12ax7 but still same value. Also I tried to adjusted vr p1, p2+,p3- but it didn't help, same value. May I ask how can I solve the issue? Thank you in advance.

When my Mjolnir SRM-006t is connected to my AGD D27, the left channel is much quieter than the right, and there's a beeping/static noise in that ear which responds to volume control. This happens to both my 950X and SR-007. The D27 is connected to my PC via USB, and does not exhibit this behavior when my computer speakers are connected via RCA. I've tried swapping the balanced XLR from left to right on the e-stat amp and and had the same issue, i.e. the issue didn't follow the balanced connection. I've also measured the voltage when the amp is on in the places indicated with identical results on both channels. Even with the D27 volume control bypassed the issue remains. …

Hello, EDIT: the original "solution" proved to be a coincidence. So, I was writing a big long post (saved below) and may have solved my own problem whilst doing so. I'm still posting just because, while the solution was one of those "d'oh" things, it might help someone else in the future. TL;DR, I think my cheapo Amazon Basics power cable isn't grounded/shielded properly and was creating a static sound in the left channel. So, if someone from Google pops in with a similar issue, check a different cable before pulling your hair out like I have. ------Problem------ I recently purchased a used Mjolnir Pure BiPolar (S/N 020) and have an intermittent i…

Dear all, I’m currently considering to up-dating my STAX-compatible HeadAmp with an extra-option of a variable Polarization Voltage . Reportedly, the SR-007 Mk2 may benefit from such a higher voltage Who has experience with such a feature ? Thanks & Regards Urs

Could someone please recommend a few Solid State headphone amps either to buy or have built. I've read so much my eyes are popping out of my head. I've got LCD X's. I've listened to a few friends tube and SS amps (Woo, Lake People, HeadRoom (older Home amp). I don't want to deal with tubes and want to go SS but can't afford Stax for a few years. You guys certainly know leagues more than I and there is no bull$itt here. Thanks.

Hi, I'm asking for help because I can't understand ... so i installed in my 006 two tung-sol 6sn7gtb tubes (American NOS)with about 250 hrs on them (so out burn-in but new), I replaced the adjustment trimmers with multiturns to have more control, I use a ceramic screwdriver, my mains voltage is 220Vac constant, I let the amp warm up for at least an hour (with signal on and volume at about 2) before calibrating, put the volume to zero and select an input with no signal (the 1, which is connected only the 3). .. tester in Vdc...first I adjust the balance or then the offset, then balance again and then offset...then I switch to the other channel now this happens to …

Hi, I’m going to use 6SN7 in my 006Ts and would like to choose something modern; going through tube specs from Psvane and Linlai it is not clear if their 6SN7 (and CV181… as here they declare only 600mA for filament that is quite strange) can work up to 330V that is the value inside the 006 in their spec (when available) we have Ua (static) … 250V Ua (maximum)…. 450V here is an example … http://www.psvane.com/en/hifiseries/327.html is there anybody that have experience about? are modern tubes suitable for use inside 006 (and similar)? any suggestion about which one should/could be choose? thks 🙂

Since Tyll and company are now out-of-biz, I'm hoping some of that company's schematics are floating around. Anyone know of a source? Thanks!

Hi, This is my first post on the forum. I have a STax SRM-323MK2 driver unit and a pair of SR-303 headphones. I would like to do some checks on the voltage levels (AC and DC if possible). Is there any service information or a schematic diagram available for the SRM-323MK2? Thanks.

I guess dCS decided that headphone-based systems are now worthy of their time: https://shop.dcsaudio.com/products/lina-system Figured most people would be interested in the amplifier so I put it in this section: DAC includes crossfeed EQ (didn't look into whether it was software/hardware), compute module on the side for either Roon or whatever dCS decides to do in-house. Looks like a scaled down version of their ubiquitous Ring DAC External clock lets you use the DAC with OCXO's instead: Full system cost seems to total 29,150 USD. Price aside I think the casework is pretty cool, I saw esoteric do similar things with some of their new …

Anyone run into one of the Wells Audio Headtrip or Enigma amps at a meet or happen to own one? They are California based. A quote from their site about the Headtrip: "heavily biased into Class A..."... They better be damn good for the money. Reviews are strong but hard to trust when so many prove to be drivel. http://www.wellsaudio.com/products/headphone-amplifiers Specifications (from manufacturer): Phone impedance: 4 to 2000 Ohms Power output: 50w/channel at 8 ohms, 25W/channel at 32 Ohms 1.8W/channel at 600ohms Distortion: <0.006% at 1Khz at .1W to 100W at 4 Ohms Frequency Response: +/-0.25db…