Do It Yourself

I could use some help with a problem I have in my father's amp. It is an integrated tube amp, Sonic Frontiers SFC-1. The amplifier has a "direct" toggle switch, which sends the signal directly from the RCA input to the volume pot,and then has 4 inputs which go through an elna selector switch and a balance control. When using "direct" nothing is wrong, but when using any of the other 4 inputs there is audible distortion in the music. I went through the tubes, checked and replaced each one with some older ones and they seem to be fine, the situation continued. I've inspected the solder joints in the rca's and the elna switch andthey seem ok. the balance control is i…

I have a couple of DIY questions: This one is pretty basic. I need an easy to use, lead-free solder. I'm guessing a lead-free eutectic solder is what I'm looking for. Is this correct and do you have any recommendations. Also, please recommend a source for it. Not that I'll be needing this information in the near future, but I have a question about Magnequest. I see a lot of other brands talked about here and almost no mention of this one. Are Magnequest not great transformers? Or maybe there is some other problem with them or the company? Or lastly, maybe nobody here uses them due to habit? I'm just curious as I know that Bottlehead likes and uses them.

I've agreed to build some Sennheiser open wood cups, and I'm wondering if anyone has a good source for stainless steel mesh? I'm thinking of using #12 mesh, and only need a small amount, about 1 sq. ft.

So I am planning on ordering a bunch of the BC546 and BC556 for the Unbalanced\Balanced board and I'll need to measure, sort, label and store them. 1. can I store them in a regular plastic parts bin with dividers? 2. can I stick labels on the pins and fold the labels closed?

Ok, I have a quick question. So, I have some of these sockets, with brackets: I need to somehow embed a nut into the bracket, so I can then secure them to the top of the chassis. I won't have access to the bottom of the socket. I don't know much about PEM nuts, but I was wondering if something like that might work. I'm leary to try an adhesive, or soldering, etc. but maybe it might work, but I'd prefer a better solution. If someone wants to make me a bracket, that's a different story, but let's assume that's not a viable option either.

I just bought some copper tape off ebay. Soooo...what should I tape with it? Biggie.

So I've been on vacation for the last few days and decided to go play with my tube amp since I had nothing better to do. After reading a whole bunch of stuff on the diyaudio forums I got a bunch of stuff together and played around with various power supplies for the heaters in my tubes. First off was a generic DC power supply I got as a kit in the local electronics store way back when. It sounds decent, with Grados there's more background hiss than I'd like but other than that I didn't notice anything wrong with it until I got the good stuff. Next was a benchtop power supply I found in the surplus shop. This is the quietest power supply, with Grados there's just the…

I have an XP portable amp from MisterX that I got a while ago. It's set at a gain of 2 (I think) and its not powerful enough to listen to classical music with the im716s. Can anyone change the gain for me?

Just curious, does anyone happen to have a variac I could borrow for a bit? If not, I suppose I could go ghetto...

I know I've seen it here before, but couldn't find it with a couple of searches. Someone told me to avoid the auto center punches at harbor freight and get one from ebay. I took a look on ebay, and see a number of $4.95 ones, plus some Starrett's that are going to go over $10 or $15. Any recommendations? Thanks, Chris

I bought this Audio Note Kits HE-6 headphone amp and had it built by a well known Audio Note kit builder, digitalpete. The amp sounds great with planar headphones but I have a problem I need help with. The volume control has a terrible scratch noise when adjusting the volume while music is playing. It will also produce the scratchy noise when the volume control is even touched while music is playing. When nothing is playing the sound is there but barely audible. I emailed digitalpete and he wants me to ship the amp back to put in a new volume pot. In looking at the khozmo volume pot it looks like there are only 11 connections to solder and all are easily accessible so…

I have been using https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k to access the stax gerber files for sometime but when i tried to today the folder shows up for literally a second in my web browser and then automatically redirects to the google drive trash folder and the web page freezes up with 100% cpu usage for the thread. I can access the schematics and spec sheets google drive folder without issue. I get the same behaviour with both google chrome and firefox. i don't know who to pm directly about the google drive issue so im making this general post in the hopes someone could investigate fix the issue. regards James

could anyone grab a few meters of surgical silk for me? I'd like to use it as a turntable belt... I know there are doctors in the audience

Someone has emailed me looking for someone to build a regulated 12v power supply that will work in france, along with the cable to make an apogee AD500 work from it. I can provide contact information, etc.

I have a Vol Pot from Audio-GD(Kingwa). They use a different way of wiring their Vol Controllers than I've seen and I wanted to hear what you guys think about the method both advantages and disadvantages. Instead of entering the POT on the input and exiting the Signal on the output after passing thru the POT, he uses the POT as a drain of least resistance it looks to me. The INPUT from the SOURCE and the OUTPUT to the Amp are on the same solder point. The POT works backwards. As you turn the knob clockwise, the Impedance increases. The Impedance is around 1 ohm when the knob is all the way counter-clockwise. The way I intepret his design is that the signal h…

Who know headphones that van been transfered to 3M Peltor Optime 105 H10A/III H540A earmuff, without soldering or using soldering glue. To create ultimate sound isolating headphones. Noticed that Urban Ears Plattan version 1 can been used for this. But i search for another headphone that can been used, without removing wires from drivers.

That they might want to sell? I'm about to place an order at Parts Connexion, but they don't carry nylon sheath. I don't want to place an order at Take Five for four feet of braid (I'd probably end up buying a set of WBT plugs or something, too.) I need about 4 feet of 1/2 inch (this stuff: Take Five Audio - Canada's Online Source For High-End Audio, Parts and Accessories - Nylon Expandable Cable Sleeve ) for a half meter pair of interconnects. It doesn't have to black. Some other color or a cool pattern would be fine (or better) If anybody needs something from Parts Connexion that's not worth the shipping, holler and I'll add it to my order.

I came home from out of state on Sunday and noticed my preamp display was awry (L-R arrows flashing, mute on, front panel non-responsive). Last night I took a look at it and it seemed to return to normal upon running signal thru it (CD->pre->headphone amp). This is a Classe CP-50, probably mid-90s vintage. From reading the owners manual, the display I was seeing is what is supposed to be there after a power outage, but I thought after 45 seconds or so it was supposed to go back to normal? At any rate, I have it open now and think I will recap it. Most, if not all original caps are Nichicon VX(M), 85C, standard series, 2000 hour life (from what I can tell). This…

I have question about how to hold a rubber sealing ring in place when closing two halves of an electronic component. I'm trying to assemble a backup controller for my ebike. I want to match up the good front from one controller with the good back from another. There is a rubber seal to go between them. The problem I'm having is that the seal won't stay in its groove dry. Would it be ok to use something like a bit of Vaseline to hold the ring in place? Maybe something else?

planning to build an electrostataic amp for my SRM L700. I have built several amps for my Moving coil earphones (HD650, K601, K702...), but never built an electrostataic one, I read some topics about it, also some diagrams of amps , there are still some questions need your help. 1. Never saw the full differential structure (for example, opa1632, lme49724) used in the electrostataic amp, why? 2. The electrostataic earspeakers have much larger impedance than moving coil ones, the only capacitive impedance is isolated by the output resistor (usually 5.1k), so...the electrostataic amp works like without loads? 3. Why the output resistor is usually 5.1k ? …

I'm looking for something small to put in my garage for blowing dust around, airing up tires, and perhaps using a small air tool with (finish nailer or something). Small and maintenance free would be nice. I've seen a couple pancakes by Husky and noticed that now Woodcraft sells a Woodriver unit that is relatively cheap. Budget is <$150. I've looked occasionally on Craigslist for something used, but nothing that is at all "new" has popped up... recommendations?

A friend and I are both building Pearl IIs. A sizable portion of the cost is capacitors. I don't have enough experience to have a well developed gut feeling for value or any favorite brands. There are basically three flavors we have to chose: big-ish electrolytics that smooth power, caps in the RIAA network that are between the signal and ground and two coupling caps, smack dab in the signal path -one is two paralleled film caps of small-ish value and right at the output we have what is specified to be a 22uF electrolytic, bypassed with a film cap. There's an armload of these things, so just buying the fanciest boutique brands all the way through doesn't seem like …

I have a Quattro I and II with different issues, appreciate anybody who has repaired CDP's. I haven't opened these up yet, doing some research first. Quattro I. Has tracking issue. Has trouble tracking some disks randomly (some 20% of the time) Quattro II. Sticking/opening drawer issue. Possible to replace the drawer mechanism? Any replacement drawer pointers? Thanks much -

Hello! I'm going to acquiere a stax srm-3 wired in 117v (originally 100v) Could you please tell me how can I switch it to 230v (France) ? Thanks you un advance!

I just bought a 1lb reel of Kester 245 solder online and the date of manufacture is 11/30/04. The website says that their leaded solder 'goes off' after 3 years. Given this is almost 6 years old, should I return it or not worry about it and just use it? Slightly reluctant to return it as Kester is not so easy to get locally here in the UK and I wanted to buy a decent/premium product for my first forays into serious (non-disastrous) soldering.