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Post by mulmany on May 27, 2019 19:11:26 GMT -6
So this is the easy part. The hard part is finding the appropriate output transformer. I love how you jump on this stuff!
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Post by matt@IAA on May 27, 2019 20:43:05 GMT -6
This one is easier.
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Post by jacobamerritt on May 27, 2019 22:14:24 GMT -6
matt@IAA - Is this the sort of project where if you had enough preorders it would help the costs go down?
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Post by peterhess on May 28, 2019 6:37:31 GMT -6
Anybody have first hand experience with the Schult eqs?
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ericn
Temp
Balance Engineer
Posts: 14,813
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Post by ericn on May 28, 2019 7:20:30 GMT -6
I keep telling Dogears he needs to get a life then he reminds me he has a wife and kids!
Looks great as usual Matt!
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Post by matt@IAA on May 28, 2019 8:46:32 GMT -6
matt@IAA - Is this the sort of project where if you had enough preorders it would help the costs go down? I don't really do that as part of my business model. But truthfully, not a ton, unless you're talking about dozens/hundreds of units. The biggest cost for these (and everything else) is switches and iron.
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Post by matt@IAA on May 28, 2019 8:48:47 GMT -6
I keep telling Dogears he needs to get a life then he reminds me he has a wife and kids! Looks great as usual Matt! I just combine nerd time with beer time while my kids nap
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Post by lpedrum on May 28, 2019 9:46:26 GMT -6
matt@IAA - Is this the sort of project where if you had enough preorders it would help the costs go down? Regardless of cost factors, would it make more sense for you to build multiple W295 "clones" if enough people were interested? Can you ballpark the cost of 1U and/or 500 series? EQ units seem to vary wildly in cost.
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Post by matt@IAA on May 28, 2019 10:19:55 GMT -6
I'm happy to offer PCBs and such for DIY-ers. I need to actually make a PCB and build one out, to make sure I don't have any bonehead goofs on my schematic, BOM, PCB. I think I could even use a standard Cinemag inductor and adjust the capacitors to get the frequency response close 'nuff to the original, and then everything could be off-the-shelf parts.
For the less solder-inclined, I could also build some, but I can't offer that "for the public" until I have built one to my satisfaction.
Stuffing a PCB for one of these is about $250 - mostly iron and switches - and that's the same for a 500 series or 1RU style. Probably $300 to DIY one, including the faceplate and such.
For a 1RU two channel, figure $800 or so to DIY. Retail for a completed unit ballpark $1200-1500, depending on final configuration (details like meters, specific transformers and whatnot).
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Post by matt@IAA on May 28, 2019 21:02:30 GMT -6
The nearest standard multi-tap inductor I could find is a bit different than the calcs I get for the original. When you're messing with RLC filters you can control the all three values to get the cemter frequency and Q, or two out of three to get one or the other. So that means you can use a different inductor, and get the same Q with different center frequencies, or the same frequencies with a different Q, but not both. So you get something like this (this is the worst one, where the Cinemag and original are off by almost a factor of 2...). So while it "works," if you're used to the original this probably won't do. That being said, I talked to Dave at Cinemag and he said it's no big deal to use the same core and wind different values. Lead time will be a bit though, I imagine...probably 6 weeks.
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Post by Martin John Butler on May 28, 2019 21:18:51 GMT -6
I have the Sie-Q, but used it only once a long time ago. I don't recall if I liked it or not, it's been that long. Is it typically used on a track like a vocal, or is it more a 2-bus thing?
I
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Post by jacobamerritt on May 28, 2019 23:22:56 GMT -6
I have the Sie-Q, but used it only once a long time ago. I don't recall if I liked it or not, it's been that long. Is it typically used on a track like a vocal, or is it more a 2-bus thing? I I love it on guitars. Electric and Bass. Snare. Vocals. Its sweet. Very musical and can be very subtle in small doses, and then you bypass and realize what you're missing.
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Post by matt@IAA on May 29, 2019 15:49:56 GMT -6
I had a chat with Sowter, Cinemag, and Jensen about this application and I think I’ve narrowed down the appropriate input to a cinemag design. Jensen really doesn’t make a transformer suitable for this input stage. I think I’m going to build one out on some veroboard and send it to Cinemag to do some testing.
I also got everything lined up for the inductors with Cinemag.
The output transformer is kind of fun, because it’s totally flexible. I have two options picked out, the same form factor, from Cinemag. One is a Quad Eight design, lots of inductance, and it will give it a real sweet tone with a nice bottom (who doesn’t love a nice bottom?). The other is the output I use in most of my designs, also steel core but very low inductance which gives some nice harmonic distortion up into the mids. I think the QE will probably sound more like the original, but the other may be pretty neat in its own right.
Still working on the Sowter options and pricing.
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Post by matt@IAA on May 30, 2019 10:55:46 GMT -6
Cinemag set comes in at $115 for the input, output, multitap and single inductor.
The Sowter set is twice that. It would be very difficult to make the PCB accommodate either on the 500 series format, so I'm going to go with the Cinemag footprint unless anyone objects.
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Post by donr on May 30, 2019 11:12:46 GMT -6
Reading this thread caused me to use the Soundtoys Sie-Q plugin on a tune I'm writing. It's great for adding some hair on a vocal, better than using a distortion plug. Nice eq too.
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Post by jacobamerritt on May 30, 2019 11:34:15 GMT -6
I had a chat with Sowter, Cinemag, and Jensen about this application and I think I’ve narrowed down the appropriate input to a cinemag design. Jensen really doesn’t make a transformer suitable for this input stage. I think I’m going to build one out on some veroboard and send it to Cinemag to do some testing. Thanks for going through all this effort! I hope it ends up being rewarding for you at least as a project, and hopefully also makes you a little cash!
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Post by jeromemason on May 30, 2019 11:53:17 GMT -6
Sowter for the transformers? They do a lot of vintage stuff that is usually drop in ready, original specs. Plus Sowter's just are amazing transformers, best IMO. But, taking the original schematic and using it for inspiration, calculating your own curves etc. A lot of work, but I will say that if I were taking a stab at the design I'd throw a post eq HPF/LPF on that EQ. I use the Sie Q on snare, every mix usually and always crank the hell out of the Low/High.
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Post by matt@IAA on May 30, 2019 12:03:12 GMT -6
Sowter for the transformers? They do a lot of vintage stuff that is usually drop in ready, original specs. Plus Sowter's just are amazing transformers, best IMO. But, taking the original schematic and using it for inspiration, calculating your own curves etc. A lot of work, but I will say that if I were taking a stab at the design I'd throw a post eq HPF/LPF on that EQ. I use the Sie Q on snare, every mix usually and always crank the hell out of the Low/High. The Sowter 3603 would be used for both input and output transformer. It’s made for bridging a low impedance source to a low(ish) impedance loaf. They don’t have a reference for the original here. No one seems to. The original schematic has an inductor LPF after the Baxandall stage, right around 20k. Adding an RC HPF/LPF would not be hard. You’d probably have to buffer it though, to keep from interacting with the other EQ portions. Not difficult, but changes the feel of the original perhaps.
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Post by jeromemason on May 30, 2019 12:17:26 GMT -6
Sowter for the transformers? They do a lot of vintage stuff that is usually drop in ready, original specs. Plus Sowter's just are amazing transformers, best IMO. But, taking the original schematic and using it for inspiration, calculating your own curves etc. A lot of work, but I will say that if I were taking a stab at the design I'd throw a post eq HPF/LPF on that EQ. I use the Sie Q on snare, every mix usually and always crank the hell out of the Low/High. The Sowter 3603 would be used for both input and output transformer. It’s made for bridging a low impedance source to a low(ish) impedance loaf. They don’t have a reference for the original here. No one seems to. The original schematic has an inductor LPF after the Baxandall stage, right around 20k. Adding an RC HPF/LPF would not be hard. You’d probably have to buffer it though, to keep from interacting with the other EQ portions. Not difficult, but changes the feel of the original perhaps. Probably wouldn't mess with it too much if you put something ultra clean like an opa1612 behind it. Not sure I'd go discrete, although there are plenty of options there, some type of drive could be put as the buffer with a push button to activate it as a drive option, going discrete that is. Might be cool.
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Post by matt@IAA on May 30, 2019 12:35:37 GMT -6
Mix in an IC with a class A circuit? Blasphemy!
Fiddling with it, if you follow the existing inductor LPF with a simple CR filter, you could make it switchable without altering the frequency response of the rest. I'll make provision for it - say, -6dB per octave with a -3dB of 70 Hz?
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Post by matt@IAA on May 30, 2019 13:14:47 GMT -6
Probably wouldn't mess with it too much if you put something ultra clean like an opa1612 behind it. Not sure I'd go discrete, although there are plenty of options there, some type of drive could be put as the buffer with a push button to activate it as a drive option, going discrete that is. Might be cool. Here's the filter (20k inductor and 70 Hz CR) showing its effect on the Bax side Without: With Here's the filter effect on mid: Here's just flat with and without the filter engaged However - it does look like you could get the thing to potentially oscillate with max treble cut without the low pass filter.
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Post by jacobamerritt on May 30, 2019 13:39:57 GMT -6
Probably wouldn't mess with it too much if you put something ultra clean like an opa1612 behind it. Not sure I'd go discrete, although there are plenty of options there, some type of drive could be put as the buffer with a push button to activate it as a drive option, going discrete that is. Might be cool. I do LOVE the ability to 'drive/boost' the saturation to taste in the plug in... Not sure how youd do that in the hardware, as its not a normal operation.
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Post by matt@IAA on May 30, 2019 13:44:35 GMT -6
You'd do it with whatever you're driving it with. You could even gain it up digitally, as long as your DA converters can spit out a high level. If the emulator is based on a real unit, that's really the only way they could have done it.
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Post by jeromemason on May 30, 2019 13:50:09 GMT -6
I always say stand on the shoulders of giants and make something great fit the modern times. Putting in the circuit to drive the unit wouldn't be massive, but it's really not as easy as the plugin. They can just copy and paste another eq, take a tap from the output of EQ1, code in a blend circuit of EQ2 overdriven and that's it. As just shown above, when you start to throw things on circuits, electricity etc. reacts. But, with that said, you'd just take a tap off the output and put in a knob that's basically a blend knob on the end of the output of the eq overdriven. That would be how I would setup a "character" knob.
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Post by matt@IAA on May 30, 2019 14:02:29 GMT -6
I always say stand on the shoulders of giants and make something great fit the modern times. Putting in the circuit to drive the unit wouldn't be massive, but it's really not as easy as the plugin. They can just copy and paste another eq, take a tap from the output of EQ1, code in a blend circuit of EQ2 overdriven and that's it. As just shown above, when you start to throw things on circuits, electricity etc. reacts. But, with that said, you'd just take a tap off the output and put in a knob that's basically a blend knob on the end of the output of the eq overdriven. That would be how I would setup a "character" knob. I'm not sure how you'd do that in the analog domain. If you're overdriving the EQ, you're overdriving it. So the only thing left to blend in is the original signal, like a wet/dry mixer. If I was gonna do it for this application, I'd add a discrete +12 dB stage with a trimpot afterwards, so you can go from +12 dB to -12 dB. But you do this, you immediately lose 12 dB of headroom. That suddenly matters if you're trying to take an already hot track and shove that bax shelf up 15 dB...
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