MXR Phase 45 clone

[McCreed]

According to this list, the Joyo AC Tone is a clone of the Tech21 SansAmp Liverpool. I haven't heard either, but the Tech21 pedal does come in the same conversations of good Vox in a Box pedals that mentioned the Catalinbread ones.

Yes that's correct about the cloning.
I mentioned this in another thread, but I owned the SansAmp Blonde and the Joyo American Sound at the same time and the Joyo sounded great. The Tech-21 was around 300AUD at the time (they're now discontinued).
I'm sure the quality of the components would be night & day, and the two main differences that I know of were the footswitch was a soft touch and the V2.0 had a a switchable speaker emulation. The Joyo speaker sims are fixed.

As for cost of building vs buying, that difference is impressive, and great incentive!
The few times I've priced out parts for pedals (with only mere contemplation of building) it's not been as economical as your numbers. However that was not any bulk buying, just one-of prices. Not to mention my circuitry knowledge is weak beyond pickups & pots!

[jugglindan]

Because the pedals are just for my own use, I have no problem fixing things if they break later on. For that reason, I am happy to use cheaper components. For example instead of Pure Tone or Switchcraft sockets, I buy bulk packs like this. And this 600 piece resistor set is about the same price as 8 resistors from Jaycar (don't worry, Jaycar still get a lot of value from me )

I haven't kept detailed expenses though, so my prices might be a little off, but not by much I think.

To some extent, you don't need much electronics knowledge to build a PCB kit or stripboard build. It's largely solder by numbers. However it does help a lot when things don't work, or when knowing if substituting one part for another will be OK (I often do this to avoid more parts orders).

[jugglindan]

Just for the record, I priced out every component for the phaser build, including items from my stash, right down to the last bit of hookup wire and the bit of paint I will need for the clear coat. Did not include tools. It will cost me a grand total of $15.93. The closest equivalent appears to be the MXR Custom Shop '75 Vintage Phase 45, which is a whopping $200

[McCreed]

...I buy bulk packs like this.

Copied this from the Aliexpress page you linked:

"Chrome nut & washer, the nut and screw closely, without nuts loose phenomenon."

LOL! I love Chinglish.
And I hate the nuts loose phenomenon!

[jugglindan]

Copied this from the Aliexpress page you linked:

"Chrome nut & washer, the nut and screw closely, without nuts loose phenomenon."

LOL! I love Chinglish.
And I hate the nuts loose phenomenon!

Agreed! No boxers round here

[samr]

Buffer: cost me ~$15. The original JHS Little Black Buffer costs $129. Most of the cost was harware, electronics are probably less than $1.

Ah, I was wondering if the buffer was one of yours. Solid thumbs up from me on the font there.

[jugglindan]

Ah, I was wondering if the buffer was one of yours. Solid thumbs up from me on the font there.

Well, I was watching Buffy at the time.

Given the theme I am planning for this one, I had better finish season 3 of TOS at the same time.

[jugglindan]

OK, JFET matching time. My other FETs are still on order, so I tested my current stock of 10 J201s.

First, I breadboarded the non-IC Greatly Improved JFET Matcher circuit:


I used a strip of masking tape on my work surface so I could write the measured values for each transistor as I proceeded. Since I used a breadboard jumper instead of a switch for the 2 measurements, I did Idss for all 10, adjusted the jumper then measured Vp for all 10.

Once I had all the measurements, I looked for pairs with close values for both measurements. I got lucky. Out of 10 FETs, I got 3 matched pairs. Two matches are very close, and the third is not quite as close but still useable. To avoid having to do all this again, I put each pair into a separate labeled bag and all the rest back in the unmatched bag.


A lot more information on this process, the circuit, and how to derive other values such as the gain and ideal source and drain resistor values, see this ROG article. But the short reason for matching JFETs is to use them in circuits that have fixed resistors to control the bias voltage to 2 FETS, or circuits that include just one trimmer that adjusts for both FETS. By using a matched pair, the single resistance value will give similar behaviours in both FETs. Unmatched FETS can be saved for circuits that use just one, or where the bias voltage is controlled separately for each FET.

The Phase 45 circuit I am building has a single bias trimmer for both JFETs, so a matched pair will give the best result.

[jugglindan]

Note, Vp is actually negative. I adjusted my labels but in the photo above I have just written the value as seen on the multimeter.

I was also happy to see that the batch of 10 J201s I bought cheap on eBay were all within spec.

[samr]

Given the theme I am planning for this one, I had better finish season 3 of TOS at the same time.

TOS or TAS!