Tuesday, 24 April 2012

Catalinbread Rah

The marketing:  The Catalinbread RAH was built specifically to nail Jimmy Page's gigantic guitar tone from Led Zeppelin's legendary 1970 performance at Royal Albert Hall. At the time, in contrast to the Marshalls that he eventually came to be associated with, Page was using Hiwatt heads on stage, modified for a bit of extra gain. The resultant sound, as captured in the Royal Albert Hall concert DVD, is enormous, and the dynamic range from these high-headroom amplifiers is nearly symphonic. With the Catalinbread RAH overdrive pedal, our good friends at Catalinbread have managed to squeeze the distinctive "Jimmy Page Hiwatt" tone into a compact stompbox. Starting with their WIIO pedal as the foundation, and combining some elements of the Dirty Little Secret, Catalinbread delivers a unique overdrive pedal that will reward the player who appreciates articulation, real dynamics, and a very amp-like response. The Catalinbread RAH is an ideal foundation overdrive pedal; just set-and-forget, using your fingers and your guitar's volume knob to bring forth a spectrum of organic, blooming guitar tones.



[24th May 2014 - new revised layout]


58 comments:

  1. Gotta make me one of these :) oh yes sir. Nice one Mark

    http://www.youtube.com/watch?v=LIQp1WRXP8s&feature=related

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    1. Bloody hell you don't mess around!

      So did it work? :o)

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  3. certainly did :)

    http://i667.photobucket.com/albums/vv31/greendogs23/20120425_085627.jpg

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    1. That's brilliant, thanks Tim.

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    2. Beautiful! How did you do that finish Tim?

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  4. nice paint job. looks like swirl painting ? warm water, borax, and humbrol paint ??

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  5. My RAH.... :o)

    http://imageshack.us/photo/my-images/833/dsc001371.jpg/

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    1. Cheers mate, Just finished the board.. sparked up 1st time :o)...

      What a great pedal! I notice a lot of drive pedals seem to suffer from lack of bass, not this! 'whole lotta love' in a box.

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    2. Ooh it is nice when they start up first time! :o)

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  6. is there a different type of test for a BS170 as ive tried the meter set to diode and check 6 ways for current passing or not..this worked ok with my other transistors and i really thought id discovered the way to know if they functioned ok before a build..tried it with the BS170's for this build and got all manner of strange numbers and only from the outside legs...if I only had a few I would consider them duff..but I have 20 or 30 of them from different batches and they all display similar behavior under testing ??

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    1. Sorry I missed this one. I'm not sure actually, I've got a Peak DCA55 Analyser so have grown a bit lazy about other methods of testing. I'd seriously recommend getting one to anyone who wants to test any sort of transistor or diode. It's invaluable for germanium transistors in particular as it measures leakage.

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  7. Do you think a 250k linear would be ok for the master?

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  8. Having trouble with this one, no drive from it, just a clean output. Tone pots work fine but gain pot acts like a second volume control. The only deviation from the original circuit is a 470n and 220n in parallel instead of the 680n.

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    1. The gain pot in this is effectively a pre-gain volume control (attenuation). It dumps signal to ground in the same way and in the anti-clockwise position only the 22K resistor is stopping the whole signal being dumped to ground. So the more you rotate clockwise, the greater the signal you hit the gain stages with. Are you sure the mosfets are ok? If you've socketed them it may be worth just swapping them to see if any have been damaged. They are very susceptible to static.

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    2. I've tried some different mosfets, got them from a mate. They were identical to the ones I had so he may have got them from the same source. I'll order some new one's and see what happens. Thanks for the quick reply by the way, I'll let you know what happens.

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    3. Im having similar issues weak gain pot and master vol are the only functioning areas. Eq is not working at all. The drains are measuring 5.7v in all three instances. Checked the layout and all seems ok in photoshop. I'm a bit perplexed tbh.

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    4. I have some problems too, my sound it's not clear, with no distortion. Maybe the diodes? static with the transistors?

      Voltages of the transistors:

      Q1- D:6.04 G:5.25 S:3.36
      Q2- D:6 G:5.24 S:3.4
      Q3- D:6.13 G:5.24 S:3.27

      I have done some photos: http://www.flickr.com/photos/77206179@N02/sets/72157631320524636/

      Juan.

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  9. It's very difficult to help from a distance for something like this. We know the circuit is good which suggests the problem is with the build or a faulty component(s) which is something that we can't check for you. Have you tried swapping BS170s? They are susceptible to static and are fairly easily damaged.

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  10. I've made about 6 of these so the layout is definitely solid. I know the gain pot is VERY clean through at least half of it's sweep and there isn't much gain available which is normal, Thats why this pedal is so brilliant as it boosts and stacks really well. The treble is very subtle but you should definitely be noticing a difference with bass and middle. The bass should be booming.

    You should make one Mark, I reckon you'll like one of these.

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  11. Well bugger, Made another and I'm now getting the same results as above.. complete clean signal.. Tried piles of different BS170's. Just thought I'd ask to see if there is any other component that controls gain I could try swapping before I rebuild it?

    Cheers

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  12. Don't all rush at once' ;o) (jokes) .. I rebuilt it and after playing it some more have just discovered that with gain and volume cranked, this is fairly high gain and f@8cking amazing sounding.... easily best drive I've tried ;o)

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    1. Hi mate, is the new one working ok or is the volume still low (hence why you can crank it?)

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    2. Hi mate, no this one is perfect, I thoroughly checked the dud board and everything is ok so I'm guessing a bad component. Just strange it's happened to a couple of other people. Must be a coincidence. It is REALLY loud when cranked so all is normal with this one.

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  13. I cannot get this to work. Traced a dozen times - issue is Q2 D voltage I think is too high - 8.8 V. Cannot find the issue - any suggestions anyone?

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  14. I''m getting the same crazy voltages as you Compulsive Audio Group for the sister pedal the WIIO traced it several times as well and no sound, maybe -8.8 v means the transistors are dead, also no LED .I May have to try a different build the WIIO from Fred Briggs site? and buy allot of BS170s. Can you hear anything if you touch the lugs on the switch as you strum I can ,also when I touch the treble & bass and pots and turn the master pot there is a scratching sound??

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  15. I can hear strong signal through Q1. Overall, there is a faint output at full volume and gain. The high voltage exists even if trannie is not in circuit. When I trace the power path, there is no reason it should be this high as the 3.3k resistor should limit the voltage to around 5.8V. I believe the high drain voltage is effectively shutting off the transistor. There has to be a short to ground somewhere, but as of yet I cannot find it. Replaced the trannie and biasing resistor to no avail. If someone has the actual voltages of a working circuit, that would help greatly.

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    1. I had the same issue with my build. I followed the voltage from 9V to Q2 drain, and its like the 3.3k resistor did nothing to bring the voltage down.

      Did you ever find a fix to this issue?

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  16. anybody tried trimmers instead of the 3k3 drain resistors...?

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  17. my build works fine (#60 ;-)) but gets a bit noisy with gain maxxed.... what about yours?

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  18. I concur this is an excellent sounding pedal. Had no EQ initially as some commented above, but realized in my haste i had neglected the off board wire between bass and mid pots! Managed to stuff it all in a zvex sized box, with a batt.
    http://i1064.photobucket.com/albums/u365/howardpowered/ec331b9766ab7e438f9751929df3e9e0.jpg

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    1. Thanks for the pic, and nice job getting all that crammed in there!

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  20. Mark, i´ve build this one (still waiting for the tonebender´s transistors) and after some debugging ive found that i had a 68n in place of the 680n cap... seems that this cap have a big influence on the sound of the drive signal. The WIIO have a 470n in place and seems to sound a little "sharper"... maybe a cap selection switch could be a nice mod for this one...
    But i just want to know if there´s some way to improve the treble response... mine sounds very good, but when put aside with my other drives, its lack that "sizzle" high end... I don´t have the original to A/B, so i dont know if its the normal behavior of the circuit or mine still have some wrong cap value.

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  21. Hi Mark/Miro
    Ive built the Sabro version of this, but its a few rows wider and a bit tight in the enclosure, Your vero certainly addresses that, but Im finding this build a little on the bright side with very little play in the treble from being ok to ear bleed territory...how can I tame this a little or any ideas where ive messed up as nobody else seems to have the same problem

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  23. Would 1N4739a diodes work? Thanks!

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  24. I'm getting the same issue as Tomo above. has the layout changed in anyway? I can remember it sounding like this, The treble has pretty much no effect at all.

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    1. I haven't updated it since April last year

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  25. Cool circuit!! My drains are all at 6.05v. Sounds awesome!! Not a great deal of gain on tap but tweaking the volume and tone controls with the gain at max., it can sound pretty big!

    Cheers, Thommo.

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  27. Hi Mark..built this and just gettin massive dc hum and abysmal sound. I just realised now, i built rev1! What was wrong with rev1? hELP!!!!!

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  28. Ok... rev1 is working fine. All the noise issues i had were due to the 9v psu. So remember.. if you plan on using a psu for this, you MUST have some sort of filtering between the 9v dc and the board. Cheers Mark another success

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  29. My build...gold case
    https://masutopedals.files.wordpress.com/2014/06/wpid-20140623_122832.jpg?w=1456

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  30. mark-was there anything wrong with the original layout of this? is that why the original is gone and rev. 2 is posted? I built the original layout a while back, but only the board. now I've come back to finish it, but the original is gone. reading through the comments it seems the original layout worked for a few people, so if its good, could you repost it? a friend of mine just picked up a genuine RAH and I'm curious to try them side by side

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  31. Hi i built two using iss1 layout and one works (see pics above), the other has volume issues (too low)-i guess i will have to socket the trannies and try different ones.

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  32. I jsut built this. All EQ controls and Master working, but the gain is not functioning. With the gain off, I get clean signal, but it quiets as I turn up the gain. Here are my voltages:

    Q1: D= 9.02 G= 0.12 S= 0.00
    Q2: D= 5.90 G= 2.61 S= 3.13
    Q3: D= 5.90 G= 2.63 S= 3.15

    I though Q1 numbers looked odd, tried swapping another BS170, same result.

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    1. Definitely something wrong with your Q1. I think the other two look good. Recheck the board for any stray solder bits or missing cuts/unproperly positioned components. If I'm not mistaken, all the readings of all 3 transistors are very similar on mine.

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  33. It seems I'm getting a response similar to that which I have previously read. The eq seems to have very little to no effect at all. neither treble or mid seems to alter the tone. Bass is fine. Checked again and again,build is fine. Is this just how it is?

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    1. You should definitely tell treble and mids do their job (although all of the controls here are pretty interactive with each other). By bringing mids down and treble and bass up you should hear a big, very distinctive scoop, and treble and bass down + mids up = a lot of mid range presence, with an almost nasal tone depending on how far you go. I like to keep the treble on mine at 11:00 or so, because I do find this pedal circuit very treble-healthy, I find the bass control is maybe the most subtle (I used Sabro's layout, BTW).

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  35. Hi there, could the zeners 9v1 be replaced by 12v zeners as they're used as static protection diodes? In other words, will the limit voltage increase sour the result?

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  36. Hey Guy, i've just built one of these, for verifying that i've done things correctly, is there a voltage chart that I can use as reference? My Q2 voltages are different to 1 and 3, and dont match anything else i've seen written in this thread.
    Thanks!

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  37. Ok to correct myself, I had not properly soldered the Grid 100k resistor on Q2, it is running now and sounds great. the voltages I get are roughly D-5.4v, G-5.0v, S-3.4v does this seem ok? I see voltages listed from guys who have problems but no voltages listed from those who have hadgreat results.
    Thank you, this has been a fantastic resource and a great fun project!

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