Do It Yourself

I have decided to go ahead and build the SR-X for my 007 MK1 and am going to be ordering boards for both the amp and PSU (ordering from pcbnet.com). If you would like an amp and/or PSU board please let me know and I will start a list. Files that were submitted are below: SR-X Board: http://gilmore.chem.northwestern.edu/boards/srx6.zip JimL Shunt PSU (PLEASE NOTE: This is the revised board KG recently updated): http://gilmore.chem.northwestern.edu/boards/srxshunt3.zip LIST: Knerian: 1 amp/1 psu n3rdling: 2 amp/2 psu No_One: 2 amp/2 psu VelvetX: 1 amp/1 psu gwrskien: 2 amp/2 psu kingofsnake: 0 amp…

Hi, I think I know the answer to this but I'll throw it out anyhow. I have some DMMs and would like to know about what you guys do with respect to calibrations. So I'll use 2 of my DMMs as an example. Fluke 87 and NEW VC99. I put them both in an electrical outlet at the same time and they both show the same V. The Fluke I bought around '96, the VC99 is about a month old. My plan is to measure some caps, resistors, etc and see how much they agree. So far the voltages measure the same. I'm not sure what it tells me if they disagree, but I thought I would just play around with a NEW meter and my Ol' Fluke. I may just send off the Fluke and get it calibra…

My HD-600 is one of my workhorses and I love them. Lately I have been having trouble with the right channel going in and out. I think it might be a bad contact with the wire but I am not sure. Any suggestions or anyone willing to take a look at them for me?

Nobel Prize on physics caught my attention this year. I've been reading about graphene and its peculiar proprieties. According to Yu

So i just build a crack /w speedball and it all went well and it is sounding great. Except that the stock pot is pretty shit and i wouldn't mind a remote control. After some searching i came across this one: http://www.tentlabs.com/Components/page31/page31.html Some specs: Input impedance: > 40 k-ohm (actual value depends on volume setting) Output impedance: < 8 k-ohm (actual value depends on volume setting) Power: AC or DC, 6 to 10V max, current max 150mA DC, 225mA AC (power connector supplied with module) Volume setting: 64 steps of 1.0 dB Channel imbalance: < 0.15 dB Inputs: 4 Input / Output connectors: Cinch / RCA (can be supplied without conne…

A good friend of mine owns a McIntosh amp and pre-amp--both vintage, probably 1970s. My friend likes audio but doesn't know too much about the technical side of things (and no, my "friend" is not me). He needs some help with this McIntosh gear. My friend's apartment building caught fire and his apartment, though not burned, was totaled. His entire apartment was soaked through due to the fire hoses and smoked through due to the, well, smoke. The gear is now sitting at an audio store in NYC, and has been for a while. He has been quoted a "repair" of $2000.00 for the McIntosh gear and a Hafler amp. He does not have a good idea of what's going on with the gear, and he doe…

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…

never mind

So I set up my lathe last night, and was itchin' to get to it today. I had a piece of East India Rosewood hanging around in the shop, and with nothing really in mind set out to make some wood chips. What I ended up with will probably end up as a post for a multi headphone stand, most likely with 4 hangers attached to a hub mounted to the top of the post and a round thick base at the bottom.

Not audio related but damn it's cool: Video: MakerBot's build-it-yourself 3D printer in action, replicator in the works -- Engadget CupCake CNC - MakerBot Industries If I had somewhere I could put it I'd be all over it. That is flat out frigging cool. Custom heaphone stands, knobs, wtf else. So cool

Hi: I just placed an order to have 10 sets of KGST boards made. A few of them are already spoken for but I should have 5 sets available to those interested. Here are some details: 1. The amp board is KGST6S4CASCODE (120mm x 135mm), the PSU is KGBHULTRAMINPSV4 (105mm x 134mm). 2. The boards are all 2mm thickness, 2oz copper, green silkscreen with white lettering. I wanted the thicker board that can better sustain the mounting and dismounting of the tubes. 3. I am using a PCB fab house in Taiwan which was recommended to me but I have no prior experience with them. 4. JimL has traced the cascode CCS part of the KGS…

I'm finally going to get back to some DIY projects. One that's been boxed away is the Bijou. Part of the reason is I want to get a case design going in my head before I get too far on the soldering. And the problem with this is I really am not seeing the kind of case I was hoping for. Oh well. Onward. My last ditch effort will be to use a fairly boxy-shaped HiFi2000 case. It is 12.20 x 11.02 x 3.14. My main concern, and the question for y'all: with this layout, am I going to pick up any RF with the transformer so close to the two amp boards at the front of the case? They will be about 6" away from a Hammond 370DAX . Here's a pic of the case size. Thanks! …

"There is no innovation in stereo amp design in a sense that there isn't any room for it, its based on an hi quality op amp chip that takes and input signal and outputs an amplified signal, the basic formula is still the same in every amp the difference is the ratio of resistors and caps and inductors used (value ratio which influences RC and LC constants in the cir), quality of components and the op amp chip" That is a quote from a local friend. We were discussing the Eico HF-81. He basically doesn't understand how an amp with bad measurements could sound good. Basically, what is truly important in the sound of an amp? I'm not into this side of the hobby but I'm s…

Hello Head-Case I am working on an amp using this transformer in a PP output from a 6h30 tube. I would like to know if anyone has had experience with wiring the secondaries in various series/parallel configurations as indicated on the datasheet for different stepdown ratios to drive different load impedances The schematics & articles I could find which use this transformer for headphone use (the Raven, and a few from Andrea Ciuffoli) dont make mention of using the secondaries this way, where other a few others with sowter & "unknown to me iron" do. I think its something worth exploring, but would like to know ahead of time if its a waste of time.

Hi, n00b here. Please dont get out your shovels or hammers, i'm just asking a honest question. I've noticed that the term "sand" has been used a lot in the DIY Forum when referring to semiconductors. Does this mean something along the lines that transistors and diodes are made out of silicon, basically quartz "sand"? Therefore: sand = semiconductor? Since semiconductors are generally not considered "passive" devices, maybe it could be a fancy acronym for Silicon Active Node Device? I've searched high and low and could only find this totally geeked-out reference: Self-Assembled Nanodielectric. Could this explain "sand"? Or is it something else? …

In my current situation I don't really have a designated area for electronics work. While trying to find a wife-accepted permanent location I've had to make due with a few impromptu work areas, all of which have really inadequate lighting. Funds are tight, but I absolutely can't afford to ruin another component attempting to forge ahead despite poor lighting conditions. I'm looking for something <$40 shipped (or bought locally) that can work well as a light for electronics work. Anyone have any suggestions on what to go for?

GROUP BUY CLOSED 13/10-2015 Probing interest for doing GB on EL34(6CA7) NOS tubes. EL34(6CA7) XF2 MINIWATT NOS MADE BY MULLARD BLACKBURN UK Matched QuadsMade in 1966-68, at Mullard, Blackburn UKThe code on the tube is xf2 B7L3 showing this is manufactored by Mullard.Tubes has been tested on an Avo 163, and matched in quads. Price: 147USD/tube (depending on the exchange rate) ....we may obtain a small discount if reaching 40 in total The supplier guarantee that the tubes are original and is able to exchange a tube that turns out to be bad with a similar xf2 Mullard as he have several in stock. Show your interest in the GB sheet: https://docs.google.com/spreadsheets/d…

Im interested in finding out as much about acoustic tubes and pipes as possible and so will be posting key and relevant information right here. I would appreciate any contributions around: -Who were the early manufacturers of piped sound translation apperatus, when did they first come out? -Models names and pictures? -Does anyone own a pair of headphones that make use of an acoustic tube, and are they any good?- whats your call on the worth of the tube?, will it go on... Cheers -Louis

Ever made something real quick, going against your feeling that it might be a bad idea? Here is one I did today. It isn't as bad as it could be - it was plugged into a fused variac - but still...

2SC4686 can be replaced by C5502D. What is the replacement of 2SA1968 for gods?

Question regarding Diptrace. I decided to try this because I was laying out a board that was way outside of Eagle's capabilities (free version). This is a vertical backplane board housing 6 pairs of XLRs and 6 pairs of RCAs, some relays, etc. Do you guys trust the autorouter? I manually placed the jacks on 1: x and 1.5: y grid, and locked them. I then manually placed the relays in the best spot (I think), locked them, then let it place the rest of the components. I adjusted some net trace widths, but let it autoroute. Seemed OK once I did a few tweaks to it, but just wanted to get some input, as I normally wouldn't trust an autorouter in a non-commercial package.

That's right. A few upgrades and tweaks for the old gal. On the list will be opamps, wiring reroutes and upgrades, power supply changes. First up, I'm going to remove these JRC4735B opamps (assuming I have correctly identified them) and replace them with...dunno. After reading up a bit it appears that these are part of the problem with this player sounding so dark. I'll have to do some comparisons, but it seems like an OPA2134 could be a candidate, or an AD8610 (or 20). Guesses? I'll have to check the pinouts to be sure.

I'm looking for suggestions of interesting DAC designs and/or PCBs/kits. I guess I'm shooting for the higher end of things, and PCM1704-based stuff has gotten my attention. So far I've found the Hagerman Chime and TentLabs kit. Any opinions on these? Anything else I should consider? Also, are there any standalone USB-I2S or analog output stage kits worth looking at? Thanks!

What can I use to get rid of nasty sticker/tape goo residue without harming a nice surface? The item in question is the VAC-1 (VDA-2, VHP-2, whatever) and I'm talking about the nice smooth finish on the front plate.

So after seeing the 60 minutes last week, and already knowing all the liquid nitrogen cooking tricks, the chemist in me idecided to try my hand at the ravioli/caviar things with the sodium alginate. Yesterday's try was a complete disaster, but today came out almost perfect. As with all of this kind of stuff, technique is all important. Its helpful to have a stash of USP grade chemicals to pull this off... So i present mohito caviar, and mohito ravioli http://gilmore.chem.northwestern.edu/mg1.jpg http://gilmore.chem.northwestern.edu/mg2.jpg Maybe we can have birgir show us how to do this...Correctly