notTHEwillienelson
Member
Upvote
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COMPLETE Wampler Ego76
- Thread starter notTHEwillienelson
- Start date
The ones that advertise as analog are analog and the ones that advertise as digital are in fact digital.
CR0SSBL4DE
Active member
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Would be just grand if their new comp is a feature limited klon into a feature limited timmy.
Robert
Reverse Engineer
It's a modified Ross compressor with clean blend and tilt EQ.
There's a filter network around the OTA stage that I can't say I've seen in a compressor before... not saying it hasn't been done before, but it doesn't look familiar to me.
I kinda guessed up front that it would have the diamond comp EQ. So that was about right.
I don't know if it's just me but I am skeptical of 90% of pedals that are "based on" some mythical studio gear.
Harry Klippton
Well-known member
Studio gear doesn't belong on a pedalboard anyway
CR0SSBL4DE
Active member
I agree that trying to emulate studio gear in pedal form sometimes misses the point of how and why guitar pedals are used.
However, there are lots of concepts and tools from studio that were and are used on pedals. From EQ topologies to low noise designs. I love my keeley compressor pro pedal, and it reminds me a lot to the SSL VCA style compressors. The variable frequency mid control in a metal zone is another example.
Except that plenty of great tones have been created with studio gear. Whether thats Lowell George or Nile Rodgers using rack compressors or Elliot Randall running direct to an overloaded board. I get why people want studio gear work-alikes. Especially as a bass player where running direct in the studio was so much more common.
Harry Klippton
Well-known member
It's that guitar amp speakers make terrible monitors. Putting those effects in a pedal format and running them into an amp is much different than post processing a recorded guitar tone
CR0SSBL4DE
Active member
Every day I see more live guitar players using modelers, and adding reverbs and delays AFTER the modeler. That way those effects are not being affected by the IR. It's a brave new world
Fretless
Member
Anyone have any suggestions around thru-hole replacements for the smd op1678’s? Would the 4558’s from that OrangeSqueezer schematic be low noise enough to give similar results?
edit:
Actually, after a quick search, maybe the TL072 is more appropriate (didn’t realize the 4558 isn’t even jfet) :
https://hackaday.io/page/21708-jrc4558-vs-tl072-what-are-differences#:~:text=JRC4558: Commonly used in guitar,high input impedance are crucial.
edit:
Actually, after a quick search, maybe the TL072 is more appropriate (didn’t realize the 4558 isn’t even jfet) :
https://hackaday.io/page/21708-jrc4558-vs-tl072-what-are-differences#:~:text=JRC4558: Commonly used in guitar,high input impedance are crucial.
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Fretless
Member
Looking further into the op amps (I deleted a probably too long post based on more info found, plus it seemed a bit overly critical), I’m going to build the GeneralTso, since a jfet based op amp is more appealing to me vs a cmos op amp, along with it’s avail in a DIP8 package.
edited to add, for anyone adventurous enough to look further into it:
Based on some other initial digging, it seems the OPA2134 used in the Tso might in fact be a suitable replacement for the OPA1678 used in the Median, but I don’t have the time at the moment to experiment with any of that or research it further.
edited to add, for anyone adventurous enough to look further into it:
Based on some other initial digging, it seems the OPA2134 used in the Tso might in fact be a suitable replacement for the OPA1678 used in the Median, but I don’t have the time at the moment to experiment with any of that or research it further.
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I play bass, my cab i built myself and could be used as a hifi speaker… when I play live it’s straight into a desk so no speakers … so studio style stuff would and does work for me.
giovanni
Well-known member
Rather than the speakers, I thought many studio effect units assume line level which is usually much higher than the guitar signal?
sticky1138
Well-known member
That's what I was planning on trying once I build it, although I am completely ignorant on the topic of IC equivalents.
Fretless
Member
Me too. I did ask Claude.ai to comare them. It seems likely at the very least some other component values would need to be changed.
Claude’s response about it, fwiw:
/claude.ai
Okay, great. Let me take a closer look at the datasheets for the OPA1678 and OPA2134 op-amps to see how well they might be able to substitute for one another.
From reviewing the key specs:
Pin-out and Package:
- The OPA1678 is available in an 8-pin SOIC package, while the OPA2134 is available in an 8-pin DIP or SOIC package.
- The pin-outs appear to be compatible, so a direct replacement should be physically possible.
- The OPA1678 operates on ±2.3V to ±18V supplies.
- The OPA2134 operates on ±5V to ±18V supplies.
- This means the OPA2134 should be able to replace the OPA1678 in circuits using power supplies within its valid range.
- Input offset voltage: OPA1678 = 0.6mV, OPA2134 = 0.3mV
- Input bias current: OPA1678 = 0.6pA, OPA2134 = 1.8nA
- Gain-bandwidth product: OPA1678 = 45MHz, OPA2134 = 4MHz
- Slew rate: OPA1678 = 35V/μs, OPA2134 = 14V/μs
Overall, based on the datasheet comparisons, I believe the OPA2134 could potentially be used as a direct replacement for the OPA1678 in many applications, as long as the power supply and speed requirements are compatible. However, I would still recommend testing it in your specific circuit to verify performance and stability.
/claude.ai
airbud
Well-known member
so so so glad to see I'm not the only one using AI for pedal design!!!! I have mixed luck with inputting schematics, but usually I'm able to figure out my question even if it hallucinates a bit. when it can lay out a PCB for me, I will do a backflip.
matmonster58
Active member
Could I run this pedal at 18V with appropriately sized up components? With all the opamps in this circuit, 18V would be nice but I don't know if that would mess up the bias of Q1 and Q2.
I'm planning to build one of these for my mandolin player. Mandolins have a lot more dynamic range than electric guitars so the extra headroom would be nice to have. All the opamps in this circuit look to be buffers or low gain so I don't think headroom would really be an issue, but i might as well run it at 18V if I can.
I'm planning to build one of these for my mandolin player. Mandolins have a lot more dynamic range than electric guitars so the extra headroom would be nice to have. All the opamps in this circuit look to be buffers or low gain so I don't think headroom would really be an issue, but i might as well run it at 18V if I can.
