Do It Yourself

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!

Been getting these lately: Dear Customer, Thank you for ordering from Mouser Electronics. Unfortunately, we are unable to obtain an authorization for your purchase from your credit card company. The most common reasons for unauthorized purchases are an invalid credit card number, an expired credit card date, or purchase has been declined as it exceeds the credit limit. Please contact us 852-37564755 to verify your credit card information or to provide an alternative payment method (such as another credit card or to let me know if you’d like to wire the funds in advance) so that we may continue processing your order. You may contact us by replying to th…

Got a regular 24v psu (no minus voltage), 100k vol pot and a small case. Best amp to build?

"Description (Gerbers) copper/pcb thicknes": Everything is one channel, and two will be needed for stereo. As for the KGSShv PSU, only the Single Right Skinny is offered: containing one High Voltage rail and a BIAS supply. Those who needs a full supply will need two of those + the Golden Reference Low Voltage. Überamp (Uber1 + Uber2) 4oz/2mm Unbal2bal (Uber3) 3oz/1.6mm Golden Reference Low Voltage (GoldenReference6) 3oz/1.6mm Transconductance Amp (CurrentSourceAmp2) 1.6mm/3oz KGSShv PSU (kgsshvpssicfetsinglenewright), 1.6mm/3oz KGSShv Carbon Amp (Carbonv6), 1.6mm/3oz Grounded Grid (.........) , 1.6mm/3oz (as requested by JoeHpj …

I have a pair of 2n5457/5458 JFETs on a small board as part of a bias scheme for a 12AX7. The circuit also has a 9v battery. I cannot get the voltage dialed down, so I checked the JFETs. The resistance from gate to source (and gate to drain) read the same in both directions: roughly 1k ohm. These are dead, aren't they?

As somewhat of a learning experience, I decided to build a PSU using the kgbhultraminipsV4 board (KGBH). All seemed to go well in assembly, and I tested every adjacent solder point for proper continuity, and ensured no cold solder joints. Used proper heat sinks on the silicon devices wires while soldering to avoid overheating them. Cleaned the board with 99.99 alcohol. I set the board up with 2x100v and 1xs150V zeners to output 350V. I plugged it into a 300V x2 transformer (smartly using a very long extension cord in the garage) it I got a HUGE pop. I was using 5W zeners, and when they go, they really go! It was the Positive side of the PSU. One zener totally evap…

I've been thinking about upgrading to a better soldering station. I am just a hobbyst so the tool is mostly for DIY work. I started out wanting to limit my budget to $200 US. As always the case, once I started reading stuff on the web, I am more and more tempted by those that are way over my budget. Right now, I am looking seriously at: 1. A JBC CD-1BD for around $400 2. A Hakko FX951-66 for around $260 I would love to hear your experience, experience and recommendations. Thanks!

AKM post a pic, but still no details...

kgsshv-carbon with the sic-fets turned into 6ca7 was going to be next year

A few of us over at another thread started by Blueman2 are contemplating getting SRX Plus PCBs fabricated. See this thread: http://www.head-case.org/forums/topic/12445-plan-to-build-srx-where-to-find-bom-boards/ Discussion of the SRX Plus design can be found here: http://www.head-case.org/forums/topic/11996-srx-revisited/ I've checked with PCBNET and we can get the cost the amp board to $25 if we order at least 15 boards. The board will be 2mm thick with 3 oz copper, the board size is 9.35" x 6.85" ( 2 channels on one board ). Kevin has recently updated the board with teardrops enabled. We have not decided on the PS to use yet. The SRX Plus needs a +/- 340VDC a…

Hi everyone, I really admire Dr. Gilmore's work, and ready to build the Krell Klone. I'm preparing for nearly a month. But my son (who is studying Shakespeare in the college), after Googling, told me, we can't just "see" the PCB and make a clone of it. (Cos the PCB has many layers, ususlly 2-4, diffrent layers has totally circuit, those copper layers are very well designed. And then he doubts Mr. Gilmore's Klone PCB image-files was drawn up on the computer after "eyeseeing".) In order to make a clone, we must destroy the PCB completely. He again told me: we have to remove all the components first and drop the PCB in a machine (can't remeber its name) and boil off the…

This thread is a follow on to the original SRX Revisited thread and the SRX-Plus Group Buy thread. As of 2024, I count at least 12 members with working SRX-Plus Amplifiers: JimL congo5 MLA Sorrodje mwl168 luca jose blueman2 Juggernaut1101 tomislavkufrin simmconn oldie ============================================================= Here is an initial Bill of Materials for the Amp. Please provide input on errors and omissions and I will update. This is my first ever electronics build, so bear with me as I learn the ropes. I am initially building a KGBH psu, so do not have the BOM fo…

I was looking for sth DC coupled hybrid power amp for desktop speaker with no caps or transformers on either input or output. While searching on google, I wanted to find jfet/tube differential, tube voltage gain, MOSFET/BJT current gain design. Then I find this. http://tavishdesign.com/pages/direct-coupled-tube-headphone-amp any opinion? Though there's a cap on the input. Any other SE or balanced configuration will be welcome.

so tyll has been going crazy over the bakoon for planars. well there are a lot of things i don't like about that amp, especially the battery power and distortion. so here is something much better, tested last night at .06%thd, no feedback, output impedance 100k which is solely due to the servo... http://gilmore.chem.northwestern.edu/currentsourceamp2.pdf http://gilmore.chem.northwestern.edu/currentsourceamp2.zip also testing curved traces

As Luvdunhill has a limit of 100 total for his mini-GB, and the the count was well above 100 not counting myself and luvdunhill, I've got a quote from Trendsetter at 5USD/ea, at minimum of 100, I've decided to organize a GB for those who still wants the LSK389B at 5USD/each, state your interest here At this point in time there are almost 100. Please be aware that the GB started as for SOIC-8 package alone. I have added the TO-71 to the spreadsheet. 20160120: GROUP BUY CLOSED

Group buy from PCBNet (same as Carbon and Circlotron Group Buy) for boards > 40. State your interest here A table and a modular graphic for easier overview of the various Golden Reference PSU boards and their function: The color scheme is the same used in the modular picture below. Options, each representing a full PSU everything needed for an amp (in the spreadsheet one can choose either): Option 1: Contains HV+/-, LV+/- and PRO BIAS. Option 2: As Option 1, but “Split” into two separate boards, making mounting more versatile. (Skinny and FAT contains the same, but Skinny is rectangular shape wheres FAT is sqarish) Option 3: Separ…

Has anyone built this balanced beast and tried it out?

I've decided to get serious about learning electronics. Tangent suggests this: The Art of Electronics 2/eby Paul Horowitz and Winfield Hill Cambridge University Press, 1989 1125 pages, hardcover ISBN 0-521-37095-7 Would you agree with this or would you suggest something else? I also plan on getting the Tube Amp text that Birgir recommends. I just need to find it again someplace in the DIY threads. Edit: Would it be "Valve Amplifiers, 4th Ed" by Morgan Jones Birgir? Or maybe "Building Valve Amplifiers" also by Morgan Jones?

Hello all, I'm working on a little project with my old SRD-6 energizer and a cheapo TA2020 amp. I'm trying to put together a compact transportable setup for my SR-5s. I have done a few modifications to this box already, such as wiring the transformers directly to the speaker taps on the back of the box and directly to the Stax socket on the front, completely bypassing the bias board and the loudspeaker switch. Those mods have done great things in terms of sound quality, but what I'm interested in now is modifying the bias circuit to operate as a self biasing one. As I understand it, Stax accomplishes this by tapping some of the output signal from one of the transformers, …

I built my original Dynahi 8 years ago and I'm going to re-case it to match my other builds and to fix some hum because the transformer is in the same case. I built a stereo version with two one channel boards powered by one PSU. I do not remember how I arrived at the value of the transformer I have now but I think it's 160 VA. The original BOM for the PSU says 250VA. Should I go up to the 250 VA spec'd in the BOM? Or is the 160 VA enough? I was thinking of trying to reduce the size of the transformer because of the hum but now I see I may have undersized it.

Hey guys, I finally found a good home in a small space for the Moth Cicadas I purchased many moons ago, and the room is conducive enough that I can really notice a bit of variance in the drivers. I have a set of unused spare drivers I'd like to sub in, to see if they are more to my liking. The only trouble is, I have no clue how to remove the old drivers. The cicada enclosure is ported, but the port is too small to fit a hand in, so I can't push the driver out from the back. It fits in the cabinet pretty snugly, so I don't have enough room to fit a spudger in around the edge and pry it up. Furthermore, being paper cones, I run the risk of damaging the old driver is I …

We're doing a quick moving T2 board set group buy; there are two members and we have a quote for two more (but will go ahead regardless). Specs are ... FR4Blue solder MaskWhite silkscreen2.36 mm thicknessENIG3 oz cuIPC-class 2100% e-TestedThe buy consists of a set of the full sized boards; one power supply and one amplifier board, $225 for the set + shipping and PayPal fees. Post interest here and we will close the buy in one week. If we have more then 4 participants the price will be lower.

As proposed, I started this thread for all to share your KGSSHV Carbon build experience and to exchange Q&A. This is a natural follow up thread to the Carbon Group Buy thread. Here are the version of Gerber files used for the boards in the group buy: kgsshvcarbonv5.zip (amp board) kgsshvpssicfetdual2new.zip (GoldenReference HV power supply, all-in-one version) kgsshvpssicfetsinglenewrightfat.zip (GoldenReference HV power supply, B+ and bias) kgsshvpssicfetsinglenewleftfat.zip ( GoldenReference HV power supply, B- and 7815/7915 based +/-15V regulator) goldenreference4.zip (GoldenReference LV bipolar power supply) goldenreference4plus…

GROUP BUY CLOSED 4. NOVEMBER 2015 For gauging interest. This GB is intended to be add-on to the MWL168 Carbon Group Buy for anyone interested in building a Circlotron. In addition to a full Carbon, two dual HV900 boards (circlotronhvpowerdualnewer2.ZIP) and two output & driver boards (kgsshvcarboncirclotrondriverv2.ZIP/kgsshvcarboncirclotron.ZIP) are needed. Currently investigating a quote form PCBNet for: circlotronhvpowerdualnewer2.ZIPkgsshvcarboncirclotron.ZIPkgsshvcarboncirclotrondriverv2.ZIPFurthermore FTCaps has been asked for delivery of the 470uF/550V caps required by the HV900 supply. The main difference between the 680uF/550V(76mm) cap and the 470uF/550V(6…

Yet Another Group Buy: Keithley 2015 THD Multimeter Except I won't participate as I have one already. The person I bought it from (in Korea) has many more for sale. Shipping is separate, so presumably you could buy them in lot and have them shipped individually to everybody from the source, pretty convienant. Pricing: (Used and functional units) more than 3 : USD $270 eachmore than 5 : USD $250 eachmore than 10 : USD $220 each It needs a central person to manage the money and information. If there is interest in a Group Buy and a leader who wants to take it, I'll forward the contact information. Please indicate your interest (how many) and whether you'd be willing to l…