Monday, 2 May 2016

Ross Phaser

This was a request.
The video is for reference only:



24 comments:

  1. Woah you're on a roll!! I thought this was a Phase 90 clone. I'll be building this one for sure

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    1. The first version of the Ross Phaser was a Phase 90 clone. Later versions were more like Small Stone Clones. More info on the Tonepad and Home-Wrecker sites.

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  2. Thanks Alex! You're the veromaster!!

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  3. Hi! I didnt see Int 1&2(sorry newbie ;))? Is it ok to use LM13700? Thank you in advance!

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    1. Int 1&2 goes to Sw 2 (it is written in the layout notes). LM13700 should be ok.

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  4. Cool. First OTA phaser in the library!

    Since you seem to be friends with LM13X00, when will we see a compact layout for for DOD FX22? :)
    +m

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  5. Hey Miro!
    I'll be glad to but how would you get rid of the switching system?
    Input at C13 (220n) and output at C11 (220n)?
    Schematic is here:
    http://www.freestompboxes.org/viewtopic.php?f=1&t=5426&hilit=fx22&start=20

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    Replies
    1. You'd probably want to keep the input/output buffer for stability. Get rid of Q2-6 and everything at the bottom. Take your output from the same place as the schematic. That way the OTA is isolated from what comes before and after it. I think anyway.

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    2. Thanks Ciaran.
      I've added a schematic in the forum chat.
      Is that what you've meant?

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    3. Threw my 2 cents in there. Can't wait :)
      +m

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  6. The layout is confirmed. I built it and it is great.

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  7. Good job . I assume you used the proper lm13600 ota's. i have two lm13700 i had three and used one for a compressor i sold last year. The only suppliers i use that had them are ebay and aliexpress. it will be about three weeks before i get them. im excited about this one.

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  8. Thanks for doing my request again Alex. I like these ota phasers. I used to have a peavey classic with built in phase. it used the ota type phase similar to the small stone i assume. Man i cant wait to do this one . ill start it soon. I have three or four pedals to build for some customers. Man they are coming out of the woodwork. Its how i fund my keepers so its worth it.Thanks again.. I ordered 5 lm13600 just in case you decided to do the daughter board on tonepad. that would be a nice addition.Thanks for fueling the fire ha ha .

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    1. You are welcome.
      I'll add the "quite large" Extra Phase Stages board in the Forum Contribution section.

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    2. Thanks Buddy. I ordered 5 in all so I should have enough. Ill definitely build the daughter board . It will be a few weeks before the chips come in from china. I need to get caught up on some boxing and trouble shooting before then anyway.

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  9. Hello Everyone,

    Has anyone built this using LM13700's? Thanks Heaps!

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  10. Thanks for the layout!
    I am a newbie, and I have built the modded version with LM13700 and it doesn't work preperly. I can hear my clean signal, but it sounds like the LFO is changing the gain instead of the phase.
    I don't have any cold solder joints or solder bridges, but I suspect that it happens due to a silly mistake I don't know yet.

    These are the measurements of the chips:
    TL072:
    1: 2.95 | 8: 9.35
    2: 2.95 | 7: 3.7
    3: 2 | 6: ~3 - 3.22
    4: 0 | 5: 2.95

    Top Right LM13700:
    1: 1.18 | 16 : 1.1
    2: 0.1 | 15: ~0.15 - 0.16
    3: ~2.1 - 2.95 | 14: ~2.1 - 2.95
    4: ~1.6 - 2.95 | 13: ~1.6 - 2
    5: ~2.1 - 2.95 | 12: ~2.71 - 3.05
    6: 0 | 11: 9.36
    7: ~2.07 - 3 | 10: ~2.75 - 3.01
    8: ~2.07 - 3 | 9: ~1.65 - 2

    Top Left LM13700:
    1: ~1.11 - 1.14 | 16: ~1.11 - 1.14
    2: ~0.08 - 0.12 | 15: ~0.23 - 0.24
    3: 2.95 | 14: 3.08
    4: 2.95 | 13: 3.53
    5: ~4.32 - 4.5 | 12: ~1 - 1.24
    6: 0 | 11: 9.36
    7: ~4.32 - 4.5 | 10: ~1 - 1.24
    8: 2.95 | 9: ~1.42 - 1.63

    Bottom Left LM13700:
    1: ~1.11 - 1.14 | 16: ~1.11 - 1.14
    2: 0.15 | 15: ~0.11 - 0.12
    3: 2.94 | 14: 2.97
    4: 3.8 | 13: 2.97
    5: ~4.78 - 5.2 | 12: ~0.68 - 0.8
    6: 0 | 11: 9.36
    7: ~4.77 - 5.2 | 10: ~0.68 - 0.8
    8: ~4.66 - 4.7 | 9: ~1.26 - 1.3

    (Tested with DMM, black lead to circuit ground)
    Is something looking not normal?
    Thanks!
    (Sorry for spamming, I wasn't sure how to edit a comment)

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    1. Found it: I somehow managed to forget to solder one end of one of the jumpers. I can confirm that this circuit works with lm13700.
      And the rate pot should be flipped, it is reversed.

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  11. This circuit uses the LM13600, not the LM13700. Try it with the right ICs

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    1. 13600 and 13700 are interchangeable. That won't cause any issues.

      I'd suggest triple checking all component locations and knifing the strip gaps. A tiny solder joint short would be my first bet.
      +m

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  12. Built, tested and verified with LM13700.
    Seems very quiet (noise-wise) and subtle compared to the Mutron Phaser 2, works best with a high input level and some adjustment like any ota-based layout.
    Good enough to box, this one. Thanks for the layout Alex and keep them coming!

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