I am Ray Ring, an electrical engineer and circuit designer. The purpose of this blog is to offer electronic design ideas, example circuits and information to other designers, builders and experimenters.

66 thoughts on “About

  1. Excellent resources you are providing Ray! I stumbled upon your site when searching for a DIY 20 watt battery powered amp. I am searching for the most audio output based on 12-15 vdc simple circuit and reasonable sound quality. Your sound clips are impressive and look forward to your thru hole design.
    Thank you for sharing your designs.

  2. Hello Ray !
    You battery powered amp really has a great sound, and the explanations of your choices for the design perfect. Congratulations !
    I was planning on building a battery powered amp, but for a voice mic (the shure , so low impedance), using two lead acid 14v batteries. I found an old portable radio that looks like a ghetto blaster, I was planning on building the amp inside for style and convenience.
    I want a clean sound with a reverb, and an additional line in for an mp3 player (for the prerecorded instruments)
    The purpose is simply to make music in the street, loud enough so it can be heard in a public, noisy area.

    Do you think I could simply modify a bit your circuit to match the impedance of the mic, and change a few values to get a low distortion sound ?
    Do you think I should use another circuit instead ?
    I have a few tl082, 741, opa2134 and 134, do you think I should use them instead of simple transistors ?

    Thank you very much !

    • it would work but you would need to create a balanced to unbalanced input for the MIC (shure SM58 for example). You would also need to modify to support the two inputs. Using some op amp stages would probably make your job easier. You can use the power amp stage and the reverb stage combined with a summing amp stage using an op amp, for the two inputs and a balanced to unbalanced (differential amp stage) for the MIC

    • I have sold a few on ebay for fun. I have a new one I am working on that I think is going to be my best ac/dc design yet. Going to build it as a single 12 inch combo amp 25 to 30 watts or so and will use a 14V lithium battery or AC.

  3. looking forward to hearing it…!! I have busked in the Boston area for 5 years now an use Taxi amps..they are good but the quality and clarity arent there…

  4. Hi, thanks for this great site! Really nice work! I have a few question about pt2399 analog delay.. First of all, is it possible to replace the mcp1804 with the lm7805? And finally which schematic did you use in the video with the endless loop? The “simplified” (REV 1.0) with the updated resistor and cap values or the REV 1.1 that we found on the top of the page?

    • yes you can use the lm7805- I like the other one because it saves couple of mA of current draw. I believe the output and input pins are reversed so keep that in mind. the REV 1.1 that we found on the top of the page? …Yes the slightly revised version.

  5. Hi there, great blog!
    I saw a few days ago an interesting PIC based phaser design, but can’t find it anymore on your blog. Do you removed it? I’d like to build one, I have already tried a non pic PWM based phaser from the DIY stompboxes forum but I don’t like the sweep. Also, I found a cool old MXR PWM phaser using CD4016 and CD4013 but can’t get it to work…

    • that design had some issues I want to resolve so I took it down. I’m working on a design that will perform better. it’s basically the same I just have to add some parts to clean up some noise. I also need to reduce current draw. I should have a new schematic posted in the next few days probably at the end of the weekend.

    • Hey there. I am not happy with the switching version yet…but I did post a vactrol version that I am quite happy with…check out the blog post and demo.It still uses the PIC and I included the source code and hex file. I’ll keep working on the switching one.

  6. I almost have the PWM version redesigned and working so I should be re-posting that this week. I use the pickit 2 or pickit 3…which is a tiny usb programmer. I think its $30 bucks it has a standalone programmer utiltiy so you can use my hex file directly or mod the code as you see fit.

  7. Hello Ray, I just purchased one of your Squeazal compressors from Sherwood music today and I’m really liking it. It’s super responsive, not noisy at all and the touch senitive light is really cool. Killer pedal.

    • I am so happy you like it….I am a player who doesn’t like a lot of knobs and complexity. So I designed this thing to give this one certain sound …which is a very clean and very tight compression. I like the light too because often when your playing live it hard to hear all nuance of your “sound” …with the light you can tell if you are crushing your dynamics or just clamping the peaks. If you ever have issues with the pedal just let me know..I am happy to support it for the life of the pedal.

  8. Good evening ray, this website and your work is great. I just stumbled upon it now and hope to build some of your schematics soon. Thanks for doing all of this work for us.

    • thanks…if you build anything..let me know how it works or if you come up with any good ideas for mods or improvements. The idea is to keep working and refine circuits and ideas so that other designers and builders can reliably replicate the designs or use as reference for new stuff. People who visit the site are so good about not giving me pointless negative comments, I get good suggestions and clever ideas ..so that is very appreciated.

    • neat …yes this is similar to what I have been working on..get yourself an FV-1 and go quadrature …it’s really fun what you can do with that! The Si5351 looks like a good part. I have been using the CS2000. Eventually I will try the Si part but I have done so much code development for the CS2000..I will need a reason to go to something else

  9. Ray, I’m know I’m late to the party, but your improvement upon the PT2399 circuits you have found sounds stellar, just wanted to drop you a line and say thanks for sharing!!!

  10. Hi Ray thanks for a great resource. I came across your site whilst rearching for a regen receiver circuit and enjoyed your demo of the circuit from your September 2012 blog. I would like to build this receiver but I am a little apprehensive about the pcb design as I know RF circuits need a bit more thought in pcb layout. Could you send me a couple of jpeg’s of your pcb layout to get me started. Thanks in anticipation and look forward to more from your blog.

  11. Mr Ring, Love your site. Your applying your education in EE very well from what I can tell. I’m a musician and somehow managed to obtain one of your Dr Cream Purple pedals and really love it. I also like the nice deeply etched and filled graphic on the enclosure. While surfing your Circuit Salad blog, I see you’ve produced many other pedals but none of which I am able to locate for sale anywhere. I know of at least one other Dr Cream that was sold on Reverb.com. Do you produce these pedals for sale? Your Orange Squeeze compressor looks like another that I’d be interested in using. Thanks for your time and I hope I can find the time to delve into some of these wonderful Ideas your having, musical and otherwise.

    Will Sautner
    The Scarlet Fire Band
    Brookfield, CT

    • Cool …Dr cream pedal…I think I sold a couple on ebay(had them on reverb also). I make an occasional pedal and sell it at Hayday music(formerly sherwood’s music) in Asheville. I hand etch each one and try to make them different from mass produced items. I haven’t made too many peedals for sale lately as I am focusing on my new business and playing in my band right now. I don’t do it for the money…more just an excuse to play music and design stuff! Is your band a Dead cover band or dead influenced? I ask because of the name. I have designed a new hybrid guitar that gives me a really nice punchy Jerry sound. I shall be posting a video demo in a few days. Thanks for checking out the site.

      • Hi Ray, thanks for the reply, I’m in a Dead cover band. One of many of late. I’ll keep an eye out for your hybrid guitar. The amp you’ve got posted sound great also and at 25watts is enough for most bar room gig settings. I recently built a 5E3 amp, My first attempt at building a guitar amp. Went off with two minor miswirings but otherwise sounds fantastic and exactly as a tweed deluxe should. keep on jammin’. I’ll keep an eye out for your posts.

  12. Ray,

    I just ran across your site looking for PT2399 projects. Your site is impressive and your projects intrigue me. I want to build the PT2399 echo pedal for my guitarist grandson. I downloaded the zip package and can see your board files. I was wondering if you have a BOM for these boards? More specifically I wanted to find out the package type for the LDO and the filter IC, and what appears to be In/Out jacks on the surface-mount board. I was an avid hobbyist some years back and now that I’m getting near retirement I’d like to pick back up on it and thought this would be a nice way to accomplish that. I’m looking forward to following your exploits.

    -Kirk Franks

    • Hey Kirk…so I have through hole and surface mount versions to fit into a 1590b hammond enclosure which is a standard enclosure for stomp boxes. You can get them in all kinds of colors..etc.

      I can give you all the info you need but I need to review all my files and organize for you. Would you prefer a thru hole or surface mount layout? Based on this I will get you as much detail as I can.

      • here is a part list with packages
        C1 10uF 1206 package
        C2 1uF 805 package
        C3 1uF 805 package
        C4 1uF 805 package
        C5 1uF 805 package
        C6 1uF 805 package
        C7 .01uF 805 package
        C8 47uF 1206 package
        C9 10uF 805 package
        C10 1uF 805 package
        C11 .1uF 805 package
        C12 47uF 1206 package
        C13 .47uF 805 package
        C14 .1uF 805 package
        C15 1uF 805 package
        C16 250pF 805 package
        C17 .1uF 805 package
        C18 .1uF 805 package
        C19 2000pF 805 package
        C20 1uF 805 package
        C21 1uF 805 package
        C22 .1uF 805 package
        C24 .1uF 805 package
        C25 .1uF 805 package
        IC1 MCP1804T sot223
        IC2 PT2399 DIP 16
        IC3 MAX7401 SOIC 8
        POT1 50k tayda
        POT2 50k tayda
        POT3 50k tayda
        Q1 SI2351DS sot23
        Q2 MMBFJ309LT1G sot23
        Q3 MMBFJ309LT1G sot23
        R1 10k 805 package
        R2 56k 805 package
        R3 1Meg 805 package
        R4 1k 805 package
        R5 2.2k 805 package
        R6 10k 805 package
        R7 10K 805 package
        R8 10k 805 package
        R9 10k 805 package
        R10 2.2k 805 package
        R11 10k 805 package
        R12 33k 805 package
        R13 1Meg 805 package
        SW1A tayda

        some notes: I get foot switches, pots, LEDS, knobs and enclosures from Tayda electronics and from bitcheslovemyswitches.com. All the other components I get from digikey or mouser. Nothing special about the caps.. or resistors. All the caps are ceramic even the 47 uf. The Pt2399 ‘s I got from ebay but if you search the web you can find all sorts of sources. Link to cad files below


  13. I love your designs. and your generous spirit. In the past I made an attempt to build the 20 watt guitar amp and failed. Could you sell me a circuit board of the latest thru hole design? If not ,I have used PCB Express in the past , do you have it there? One way or another I would love to build it. Thanks again for your great contributions…..joejazzman

  14. oh no…sorry it didn’t work for you…let me look at what I got kickin around..my home lab is all boxed up because of renovations but it think at my office I have a bunch of boards and parts for these…let me look and get back with you

    • I have some stomp amp boards that are mostly populated, you will need some POTs and the jacks – which could either be PCB mount molded jacks that I use in my stomp amp boxes or wired panel mount jacks on a chassis. The stomp amp kicks ass and I think you would like it. I could send you one of those? It would not be a complete build from the ground up for you, but still plenty to do in order to make a quality portable amp.

  15. Ray, I am having trouble with the audio compressor, final version of Oct 2012 with two 2N7000.
    The 50 K pot has to be set way down less than 500 ohms to get any sensible operation. The amplitude out varies with frequency by at least a factor of 3. I have checked my work, and simulated it in CircuitLab.
    In CircuitLab, the amplitude out basically goes to 0 after 1 cycle of the input at 1 KHz, no matter how small I make the input amplitude.

    • Well – not sure what is happening, but I will revisit it and see what might be the issue.. Maybe I have an error in my schematic? Its been awhile! let me get back with you in a few days.

  16. Hello Ray,

    I am a beginner in electronics and I would like to build myself a few pedals in time…

    Please help me with this: what is the difference in terms of electronics for the construction of fuzz, distortion, overdrive, boost pedals? Why are there one pedal for all? I mean other than the commercial reasons…

    • there is much subjective terminology here and overlap but I will give my interpretation: An overdrive usually attempt to create the distortion sound you get from over driving and amp…so usually this would be achieved by creating high gain amplifier stages in cascade with variable gain and perhaps tone adjustment ..to soft clip the input signal. A good example of this would be a 4049 hex inverter overdrive pedal(all over the web). A distortion pedal could be the same thing but typically a distortion uses diodes, fets or some other method to directly clip or truncate the signal and can produce a grittier or stronger distortion. Typically, a very high gain amplifier precedes the diodes or they are used in an amplifier feedback circuit. This allows for very long note sustain and a super compressed singing type sound. A good example of this is a tube screamer. A Fuzz is typically an extreme form of distortion where the waveform is very abrupt in its transitions(no rounded edges) and has a very bright and harsh sound with much harmonic content. Often this is achieved with driver bipolar transistors to extreme levels with skewed EQ or using diode doubler circuits to create octave doubling as well was distortion to add to harmonic content. A boost pedal usually is an amplifier stage that can just be brought to cusp of distortion by overdrive and typically will have treble boost help make the signal cut through the mix better.

      what can really affect the sound is: the symmetry of the distortion (is the top as clipped as the bottom or some variant), pre and post eq of the signal chain, using diodes for clipping, using bipolar transistors for clipping, is there feedback in the signal flow.

  17. Hello Ray, I’m an ancient analogue design guy, and was in hifi many years ago. Looking at your EL84 amplifier reminded me of an old dodge to get more feedback round the output stage including output transformer. This is to merge feedback from primary and secondary, so that LF feedback is from secondary and HF feedback is from primary. This overall yields stable operation whilst avoiding the HF phase-shift that plagues output transformers. Hence you can apply more feedback and get better linearity. Hope this makes sense, mike

  18. The website is helpful for my home tinkery. I’m trying to make the phaser you have on here w/ the PIC, but the hex file keeps coming up as “corrupt” when I try using on my programmer. Has anyone else run into this? Would you be willing to email it to me?

  19. Hey Ray, I bought one of your squeezle pwm compressors at Heyday music years ago. I love the pedal and was wondering if it would be possible to get another one? Thanks, John.

  20. Hi Ray!

    Re: your SDR receiver based on the FV1:

    Is the FV1 digital audio processor the same as the AL3101? Did you take any measurements on sideband suppression or do you know of any metrics that might allude to that? AL3101 chips are available on Ebay and I was thinking about using one as a Hilbert filter in a phasing receiver, mush as you did.


    • No its not the same. The FV-1 is audio in audio out unlike the AL3101. Sideband suppression is a function of the algorithm used… the FV-1 itself as hardware is not going to be the limitation. With the code I developed, the and using a Si5351 clk generator in quadrature…I was able to achieve approximately 60dB suppression. The accuracy of the quadrature and the accuracy of the IQ amplitude into the FV-1 is the most important issue

  21. HI Ray I am just getting started in reading schematics and have a question about your ring modulator design if I may ask? Please could you tell me how many tso922’s are used in the circuit please?
    I saw there is IC1A and IC1B also IC2A and IC2B Are there 4 tso922 or just 2?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s