Author Topic: Choral Reef  (Read 2012 times)

gordo

  • Electron Doctor
  • *****
  • Posts: 1122
    • View Profile
    • Project Website
Re: Choral Reef
« Reply #30 on: August 08, 2017, 08:41:52 PM »
Plus I figure I'm paying Steve back for sticking his neck out to stock these.

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #31 on: August 10, 2017, 09:03:07 AM »
I wouldn't buy outside of SmallBear unless it came from a reputable source, ebay🤣 Since my vacation screwup I'm strapped for cash. I should have most parts in the bin though

somnif

  • Solder Ninja
  • ****
  • Posts: 474
    • View Profile
Re: Choral Reef
« Reply #32 on: August 12, 2017, 02:18:47 AM »
How important is the 14k3 resistor values to be exact? If I don't have to order such an odd value it would be really swell. Would 15k work?

If we use the old EHX wisdom, super precise resistor values on schematics usually meant "these guys are important, check their value to make sure they're in spec", rather than needing that specific exact value.

In this case, looking at the schematic, I would say just buy 20~ 5% tolerance 15k resistors and meter them to find 4 that are all fairly close to one another on the small side of the range. They wouldnt need to be 14.3k exactly (since they're all in line with the pot after all), but they should all be about the same value.

(And yes I'm mostly writing this to talk myself out of buying 200 14.3k resistors from Mouser since that is their minimum order...)

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #33 on: August 13, 2017, 06:13:47 PM »
I'm putting my orders in for the various parts this gem will need but Is there a alternative to the TLE2074? While searching this, I found a similar question on this here on this forum. Some one was looking for a alternate to the LF347, both quad op amps and the TLE2074 was suggested. LF347=75cents &TLE2074=6bucks

somnif

  • Solder Ninja
  • ****
  • Posts: 474
    • View Profile
Re: Choral Reef
« Reply #34 on: August 13, 2017, 06:18:31 PM »
I'm putting my orders in for the various parts this gem will need but Is there a alternative to the TLE2074? While searching this, I found a similar question on this here on this forum. Some one was looking for a alternate to the LF347, both quad op amps and the TLE2074 was suggested. LF347=75cents &TLE2074=6bucks

The tle2074 is basically a super high end tl074. Triple the slew rate, twice the bandwidth,  all the bells and whistles.  In theory the 074 should drop in. Try it, if unhappy you can then get the tle2074 from arrow with free shipping later.

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #35 on: August 13, 2017, 06:34:56 PM »
I figured the reasoning was the all around quality, VFE's arent throwing in crappy noisey parts. Thanks

madbean

  • Administrator
  • Electron Doctor
  • *****
  • Posts: 7524
  • Brian
    • View Profile
Re: Choral Reef
« Reply #36 on: August 14, 2017, 05:58:34 AM »
Yeah, I don't see any reason for a TL074 not to work. I'm sure the TLE2074 was chosen in keeping with the idea of highest headroom / fidelity as possible. An alternative would be a different rail to rail like the TLC2264 which should be about half the price.
I own madbeanpedals (duh). I am part owner of Function F(X).

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #37 on: August 14, 2017, 09:08:43 AM »
I started ordering parts, some from SmallBear/Tayda and tonight is Mouser. I don't understand the rail to rail lingo but I do see the pin out is the same. Maybe I'll get a TL074/TLE2074 and the TLC2264 to compare. I watched the video from switching board link. These vfe's are some serious thought out effects. I'm still sorting out quirks on my Tourbillon and thinking I'm screwed if I have to trouble shoot this

madbean

  • Administrator
  • Electron Doctor
  • *****
  • Posts: 7524
  • Brian
    • View Profile
Re: Choral Reef
« Reply #38 on: August 14, 2017, 09:24:50 AM »
Many op-amps are designed for bi-polar supply (+/- DC) but are limited in how much a voltage output can "swing to the rails" during operation. A rail to rail op-amp is designed to run off a single supply (here 9v) and the output can get very close to the positive rail while maintaining a high dynamic range.
I own madbeanpedals (duh). I am part owner of Function F(X).

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #39 on: August 14, 2017, 09:43:18 AM »
Thanks for the explanation, so if you needed more voltage for bigger headroom your not getting it from this rail to rail chip. I like headroom,  TLE2074 it will be

BrianS

  • Electron Doctor
  • *****
  • Posts: 600
    • View Profile
Re: Choral Reef
« Reply #40 on: August 14, 2017, 04:44:03 PM »
I'm still sorting out quirks on my Tourbillon and thinking I'm screwed if I have to trouble shoot this

The VFE projects are the easiest pedals I've built.  One thing I've noticed is there's not many, "I'm having a problem," posts and the ones (mine and one other) were self induced mistakes.  I finished my Choral Reef yesterday and after fixing the power wires which were switched wrong the pedal fired right up.  So that's 3 for 3 on these knock on wood. 

peAk

  • Electron Doctor
  • *****
  • Posts: 1126
  • Justin - Houston, TX
    • View Profile
Re: Choral Reef
« Reply #41 on: August 15, 2017, 06:01:48 AM »
is everyone building this with those small pots or are some of you doing offboard wiring to regular size pots?

somnif

  • Solder Ninja
  • ****
  • Posts: 474
    • View Profile
Re: Choral Reef
« Reply #42 on: August 15, 2017, 06:32:51 AM »
is everyone building this with those small pots or are some of you doing offboard wiring to regular size pots?

I'm building to spec: 2x 9mm pots, 3x 16mm pots, 1 switch. The 9mm's are the plastic shafted variety used in the production model.

Not a lot of room in the 1590B to move things around I'd wager. The layout is about as size efficient as it can be.

lego4040

  • Stompbox Star
  • ***
  • Posts: 212
    • View Profile
Re: Choral Reef
« Reply #43 on: August 15, 2017, 10:45:54 AM »
I bought everything as per spec except enclosure so far. Measure 10xs then drill once🙄

peAk

  • Electron Doctor
  • *****
  • Posts: 1126
  • Justin - Houston, TX
    • View Profile
Re: Choral Reef
« Reply #44 on: August 15, 2017, 11:40:30 AM »
is everyone building this with those small pots or are some of you doing offboard wiring to regular size pots?

I'm building to spec: 2x 9mm pots, 3x 16mm pots, 1 switch. The 9mm's are the plastic shafted variety used in the production model.

Not a lot of room in the 1590B to move things around I'd wager. The layout is about as size efficient as it can be.

oh yeah, I was just thinking about going a little larger on the enclosure.