Do It Yourself

Hi, I'm wanting to buy a VariAC. Here's one from MPJA, hows it look? 2KVA 0-130VAC VARIABLE TRANSFORMER-MPJA, Inc. This one seems to have the amperage to do anything. Les

I'm trying to make a Super Symmetry Dynahi (not dynalo) the best possible way. (without getting in the ridiculous). Anyone could direct me to the up to date gerber files, a BOM, any other resources are also appreciated. Also if any of you previous builders have recommendation on best practices and what to avoid while making the susy please share ! Thanks

So as most people know, the Qualia 010 Medium-sized headband is actually too big for most people. I have the M-sized headband myself and have been struggling to get a nice fit with it. At first I was using a folded-up linen to close up the space between the headband and the top of my head but it always felt ridiculous (and looked ridiculous too) so the other day I began looking for a better solution and one day while doing some routine cleaning, I realized I could use a sponge! Yes, a sponge, and it ended up being perfect - just the right amount of leverage and comfortable too. There was only one last issue, how to attach the sponge to the headband without causing any dam…

I am probably starting to much thread here but anyway, here is another one. I heard about the Bamaslama amp, and now I want to build one. schematic: PSU amp Is the relay needed because of the power supply design ? Does it make a "plop" when you power the amp ? Can I use cheap dual op-amp or something special is needed there ? Then what kind of relay do I need ? Are all resistors 1/4W ? Do i need matched pair for the second stage tube ? What will be the DC offset like ? What is the filament wiring like ? What will be the approximate price to build it ? I will use cheap coupling caps in the first time. Lots of question as always,

My b22 has felt feet and is in dire need of something, anything better that will provide some lift. Also what version of loctite is safe to use on nuts, bolts, screws, pots inside the amp? Things were pretty loose when I got it and have been tightened but I'd like it to be a one time thing

I've been messing around with a Counterpoint preamp I have owned for several years on and off. It's always had a slight amount of hum, not real bad, but it bothered me. Over the years I've managed to make it worse, and then much better, but never quite gone completely. After dealings with a couple of former service techs on diyaudio, I finally decided to try once again to rectify this. I was prodded to look at the PSU, particularly the heater supply (I'd already done some work and parts replacement in the HV section). Looking at the heaters, I had recalled seeing some ripple on them back when I rewired the umbilical (both before and after). About 50mV of r…

First, sincere thanks to everyone who contributed in the forum.I cannot start the project without resources from here. Recently I have finished my KGBH build but it isn't working.The observable problems are the two LEDs connecting 2sa1968 and the one connecting 2sc3675 do not light up as well as those 1968s not heating.Curiously, the amp works for a second every time after i turn the power off,right after the extinguish of the leds connecting the + and - 15v supply. The PSU unit is measured of giving the right voltage. I once thought of giving up the project but before that I try my luck to see anyone who once encounter the same problem or know anything about it. Th…

Does anyone have these issues in PDF format by any chance (I've read a few great articles but they were only pieces)? Thanks

I need help putting together a simple TTL converter circuit to raise three DSD / SPDIF3 signals up to TTL level. I'm tapping the lines off a TI DSD1608. Here's what I have so far. Specifically, I was looking at a single TI SN74HCU04D for all three signals. Any recommendations on the cap here? I was thinking all surface mount here, but whatever the consensus is for the caps, I'm fine with. I'm thinking of adding a regulator as well nearby, like a National LP2985 5V regulator, or similar. Currently, these SPDIF3 lines won't leave the single box player, but perhaps down the line I'd route them to an external box via BNC cables. Either way, I'm assuming a single buffer…

Had a few transformers from ToroIDY with two 115V primarys I needed to serialize, unfortunately no markings of the phase. Hook'ed up one of the secondaries to a function generator, and serialized the two primaries. Having two free leads and two connected leads (CT) Measured the voltage V1 from CT to one lead, and V2 from CT to second lead. Finally measured the voltage V3 from lead to lead. If V1 + V2 = V3, then the two windings are in phase. If V1+V2 ≠ V3, the the two windings are out of phase. Are there an easier way of determine the phase of transformer windings?

Have any of you that have the IM716, or took advantage of the Buy dot com deal, removed the volume pod and added resistors? The other site has a thread on this but thought I check here as well. I just got in a pair and also have a few resistors hanging around; although, all I have are 75 ohm jobbies from KSC-35 mod craziness. Other than getting rid of the somewhat sizeable pod holding the switch and volume pot, anyone find it worth the effort?

Thread for discussion of the Shiguraki clone "Shigaclone" CD transport I have a couple at my friends place in Canada I should get them shipped sometime...

updated Megatron schematic. If you manage to figure out what the stax mafia is doing, please let us know. We are having a hard time keeping track of it all

Not sure if this is the place, but I need knowleadgable people abou the subject so here we go: I study design and I'm thinking about building a hybrid headphone/computer speaker, and was thinking about the difficulties of this. I'm uncertain if it's at all possible, because I'd have to meet the sensitivity and dB output of both a regular speaker and a headphone speaker. And I can't actually design one (I'll only design the prototype around it), so I'd have to use something that's already out there. Sound quality is not really a concern, it just needs to be acceptable. One thing I considered was to have a regular driver (sort of those used in laptops) with some kin…

Greetings. I recently bought a used Sennheiser HD600 from a friend for practically nothing more than a song, knowing it had problems with the cable on the right side. There is intermittent continuity, so the audio keeps cutting out if the cable is moved just so. I know there are several manufacturers that make replacement cables such as Clou and Cardas, but I don't feel like spending CAD$200 on -wire- right now. (yes, some of you will call me insane for not immediately picking up the Cardas or Clou cable. Well to that I say phthptftphfftt!!! ) Anyways, I was wondering if anyone knows where to get the seemingly proprietary connectors that Sennheiser uses in their headphon…

Since I discovered electrostatic headphones two years ago, I have been wanting to build a Blue Hawaii. Thanks to the generosity of Head-Casers Nattonrice and Wink, I've got my chance. They supplied the board sets FOR FREE! I am so stoked, I cant thank you guys enough. For whatever reason, I enjoy doing quirky builds. Aesthetics have never been my thing. (prolly because I'm a cheap bastard) I like to instill some sentimental value in my creations along the way. This KGBH isnt going to win any "best of show" awards. It will fulfill three of my objectives: 1) Be totally encased / covered. My listening space, the living room is also shared by two rowdy teenagers …

I just finished making the Wenge trim piece to overlay the damaged plinth on the Mitsubishi LT-30 that I bought a few months back. I'm happy with the way it turned out. There is a very slight lip that I milled that covers the top edge of the plinth where there were a few chips. Most of the damage had been at the corner of the plinth where something had struck it and crumpled the MDF. Here's a couple before and some afters...

As many of you know, APL is being flaky as ever so I might as well keep my 3910 since it works well for my needs and sounds pretty good. I do have two major problems with it though, first of it is 117V only and the second, it is not silver. The solution for the latter is pretty simple, I just bought a Japanese 3910 for very little money (which are champagne colored) so I'll just move all the trim parts over and gain a replacement drive too boot. That player hasn't arrived yet so I'll tackle it at a later date. As for the issue of 117V, well an outside step down transformer is just a pain so why not try to mount one internally? Since I was ordering some transform…

As stated in title, if I can build an interconnect, can I make a power cable? Anything special I need to know so that I don't burst into flames?

Hey, I was wondering if anyone might know of other attenuation curves, other than the standard log? What I'm thinking of is something that uses multiple logarithmic slopes, but I cannot really expect this to be a novel idea on my part. I have an idea that I'm working out, but was wondering if there was anyone else that has gone down this path? My one requirement is constant input impedance My second question has to do with SMD resistors. I'm looking at the Vishay Dale TNPW and Susumu RG/RGH (due to vanishingly low tempco values), but was wondering if there were other lines out there you guys might be aware of. I'm focusing on thin film resistors at the moment (unless t…

Looks like Heath kit will be coming back to business. Source Has anybody played around with heathkit's stuff back in the day?

So it turns out that the lme49830 is pretty much a dynafet on a chip, with diamond buffers driving the fets. SO... combine with the semelab-tt lateral audio mosfets, and the result is something super sweet, and easy to build, about $50 in parts per channel. Combine 4 channels with my balanced preamp, and have one serious kickass thing guaranteed to drive anything, he6's and k1000's included. At about 2 orders of magnitude less distortion than that other thing. And more than 10 times the available output current. at... 20hz to 20khz... .1mw .05% thd (most of which is noise) 1mw .01% thd 100mw .005% thd 1w .0003% thd many watts <.0001% thd …

So I was thinking of building a linear psu for a new PC. I came across this kit on ebay https://www.ebay.com/itm/LPS200-Linear-Power-supply-kit-board-LPS-DC5V-9V-12V-15V-19V-24V-28V-L164-5/111964387845?hash=item1a1198fa05:m:m3fiLyO2CiBO8ZWg77rtjeQ Anyone ever use something like this kit? The Teradak products are really cool but pricey

Colors Sovietized for effect * this should be in DIY forum

Hey I've got a seduction phono preamp that's developed a problem. I get a low level: thu, thuk, thuk, thuk sound out of both channels. it's not bad with the stock tubes, but with a pair of amperex bugle boys it interferes with the music. It's a fast rhythmic pulsing that is channel independant (shows up in both). I've tried replacing the caps in the PS and the heater PS since someone on the Bottlehead forum suggested it might be "motorboating" but that didn't work. All voltages check out on the amp except pins 1 and 6 on each tube. Both should measure 70V, but one measures 73 on one tube and the other tube it's 67. Any help would be appreciated. Oh yes, …