Do It Yourself

So I want to print a holder for some supercaps. Anybody here disign in 3d regularly?

Hi All: This is the build thread for the Kerry design PSU. I posted BOM and schematic with Kerry's permission here and will be posting more information including photos of my test build. My test build use the partially-assembled GRHV boards. I soldered in the the pass transistor and the resistors to set up my desired output voltage. The voltages, timer all tested as expected without load. Fire up your soldering irons and happy building! GRHVBase-v2-production.pdf GRHVBase-BOM - V2 production.xlsx

The speaker protection i have uses 2 relays for stereo channel (1 relay for each channel). But I'm thinking of using it in "mono-mode" and shorting the R+L input and R+L output to make it more "robust". Will that work? (this would mean I would need 2 devices for 2 channels.) Thanks again

As above. The 2 DACs I have already haa digital volume control which I believe are provided by the AKM/ESS chip. Thanks

There seems to be some consensus on the voltage requirements for electrostatic headphone amps. Nearly all of the commercially available designs put out between 1000 and 1600 volts peak-to-peak, a range of about 4 dB. The legendary Stax SRM-T2 was specified to put out a bit more, close to 1800 volts peak-to-peak, which is 1 dB higher. This would be equivalent to almost all loudspeaker amplifiers putting out between 50 and 125 watts, with the T2 being like a 160 watt amplifier. However, there hasn’t been much discussion on the current demands for electrostatic headphone amps. Output stage currents in commercial amplifiers have run between 2 mA/channel (Koss ES950) a…

For the bias voltage, I will be using a DC power supply I'm getting from Ebay: Bertan PMT-10C/N -1 kV 4mA Adjustable High Voltage DC Power Supply. Even though this supply takes in a DC input, the spec sheet says: "These fully enclosed modules are specifically designed with proprietary linear power conversion techniques to provide exceptionally low ripple and noise" Not sure how they can get a regulated high voltage from +24 VDC using "linear techniques", but in without using a switcher, but anyway, my question is: Is it necessary to ground one side of the bias supply? That is, connect it to chassis, U ground and audio ground? Is it necessary or useful for one …

So, gathering interest for collaboration on KG's Dynafet. The way this would work is quite simple. There would be a group buy on parts as well as the boards. The parts would be supplied by myself and we'd work a deal out for people contributing in the matching efforts and various aspects of specing and acquiring parts. The boards would be the Hitachi version with external heat sinks, using KG's latest board files. Front end would be constructed from devices matched from a pool of 500 2SJ74BL and 500 2SK170BL matched to 20uA accuracy. All devices were pulled from original Toshiba packaging. Actually matched to 10uA with +/- 20uA measurement uncertainty added on t…

So for whatever reason a number of different projects are coming together at the same time. This is the latest. http://gilmore.chem.northwestern.edu/kgsshv.jpg Its the high voltage version of the kgss with higher voltage pnp transistors, a cascode current source for the 3rd stage, the lsk389 part (or singles) and much higher voltage output transistors. The result is something that runs on +/-500 volt power supplies, and is as close as i know how to do to the T2. (except fully solid state, and easy to build) The transistors that go on the heatsinks are already insulated, which makes that part easy. Not a lot more money than an exstata, and much better sound. …

Anyone already bought this one and/or seriously considering it? Seriously tempted to try one against my M-Dac with the added bonus that it could drive my T1s directly More info: http://soekris.com/products/audio-products/dam1021.html https://hifiduino.wordpress.com/2015/01/30/building-soekris-r-2r-dac/ and a couple of gargantuan diyaudio-threads //UFN

Well its not like the stax mafia aren't busy and we certainly are not going to do an output stage with 8ma of current, and therefore no reason for a 4 stage amp, and since tube inputs seem to be the big thing lately, well might as well take the kgsshv-carbon design and replace the input fet with an input triode. bonus, no low voltage supplies. not a bonus, ksa1156 and ksc5026 run at close to 1 watt each. I should have a real t8000 end of june, but this should keep some of you busy. I expect joamat to have one built in less than 24 hours. no, no circuit board yet about 70 volts on the plate of the tube, same as t2. optical servo from kgsshv-carbon…

Colors Sovietized for effect * this should be in DIY forum

It happened finally. Something killed the power supply on my apogee ensemble. No scorch marks visible, no fuse i can find, it just doesn't power up anymore. I've emailed apogee, but they stopped supporting these a few years ago. I just don't have thunderbolt on my mac pro, and really don't want to go through all that. So I'm torn between replacing it with another one, finding someone to repair it, or getting a metric halo.

Now that the PCBs are finding their ways to us -Balanced Dynahi Builders-, I think that it's time for starting a build discussion thread for this beloved amplifier. The purpose of this thread is to create a place for builders to discuss all topics related to the build of this amp (parts, constructions, troubleshooting...), to share experiences and to consolidate the information and discussions about this project. Schematics of the Balanced Dynahi and the associated Power Supply by KG. Background information about the original KG Dynahi can be found here. Based on the preliminary BOM posted by Lil Knight earlier, an updated version for the Dynahi and the assoc…

Does anyone have schematics for either the Gold (balanced?) or the unbalanced version of these? I told a person I dealt with (diyaudio user) that I thought they might be available (and told him why bother), but his interest is just in the front end section as a preamp). I saw what is available on the eservice info site, but can't remember my login there. The user says he has some incomplete schematics with pencil markings on them. I had the attached jpeg, but think this could be what he already has. Thanks for anything you can find.

Has any one of you done something like this, accommodating a pair of RCAs and a pair of XLRs, with the appropriate switching for these? I know I'll get told to just use the Neutrik or whatever RCA->XLR adapters for this, but I was thinking about doing up a PCB with a pair of something like the Neutrik NC3MAV/FAV and a pair of RCAs. Has anyone ever used the vertical Vampire RCAs (pcb2f/s)? They don't list any dimensions or PCB layout for these, but just wondering height-wise if these could work well? I had thought I would probably use relay switching instead of a mechanical switch, as the 4PDT are a PITA to wire up, but I suppose just going into a board with c…

Hi All: I inquired TKD Japan directly about their 4-gang volume pot 4CP-601 and they referred me to their US distributor. Long story short, looks like I can get the 10K pot for $65 a piece plus shipping. The cost may be slightly lower if total quantity is high. I am still working out some detail information. Any interest?

Anyone have CFA3, GRLV, or headphone protector boards available for sale? Thanks!

Hello, new to Head-case, but an experienced elec tech. After demoing a friend's, I'd like to build a balanced Dynahi, but am having troubles tracking down documentation and boards. Can anyone steer me in the right direction? Thanks!

http://www.ebay.com/itm/322416989057?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Looks real in the pic and has a pic of a lockyz output from the curve tracer. Gets good feedback and all. Still no real way for me to tell from the pics. I was hoping to buy a set and ask one of you more experienced users to test them for me to see if they meet original specs.

So after a successful T2 project, it is time to tackle something i've been playing with on and off for quite some time. The KGITSOJC The Kevin Gilmore in the style of John Curl preamp. Now if you want to read over 700 pages of babble and bullshit, you can go over to diyaudio and read the two threads. But suffice it to say that the Blowtorch circuit sounds very good, but JC is of the opinion that only 2 people in the world are capable of building and getting the thing to run. I kind of disagree with that because i have one exact copy of the blowtorch amplifier running right next to my version. He has some reason to say this, parts matching is ultra critical,…

My beloved KGSSHV died, one channel went up in smoke. Tried to fix it but I cannot find the fault. Would you be willing to help troubleshoot? I’ll gladly pay for any help, want to get my amp back to work.

I think I'll ask santa for a good desoldering station this Christmas. It would be for through hole work, can anyone recommend one that works well for them?

Hi, I recently bought an L300LE, and unfortunately the mechanical part of the headset is rather poor...particularly the plastic frame and the headband adjustment, the former desitinated to break with use because it was too fragile, the latter simply does not hold the set position due to the weight of the headset...I had to put bluetack on it to lock the two slides in place the aluminum frame of the 700 is much better.. but the cost is insane! simply crazy! has anyone made anything DIY to replace these shoddy parts?

Both Birgir and I have wanted one of these for quite a while, and they never seem to show up. So with a little help from one of the members here we were able to reverse engineer this one. http://gilmore.chem....rn.edu/ksa5.pdf http://gilmore.chem....rn.edu/ksa5.jpg still have work to do on the power supply. All the parts are still available, but identical and compatible parts also available. mpsw06 and mpsw56 and lsk389 I think this one is fairly cheap to do. And easy to assemble. Single channel is 10 x 3.65 inches. Single ended not really a HE6 killer, but balanced, a HE6 heavyweight for sure. If you replace the servo opamp with opa445, then you …

The saga of messing with my 2nd Carbon build continues. Since the circuit is very close to the Grounded Grid, I'd like to give it a try. Being hesitant to spend big bucks on a nice quad EL34, I have been on the lookouts for a cheaper substitute. The curve of a pentode looks a lot like that of a SiC FET. I need a pentode with the following properties: The plate curve should have low kinks or no kinks at the low Va range. The lower the 'knee' the better. Low Ig2. Ig2 should be much smaller than Ia (20mA), ideally 1mA or less under the operational Va range such that Ig2 doesn't interfere with cathode drive/ cathode degeneration. The amount of negati…