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Post by jeromemason on Aug 3, 2015 23:04:59 GMT -6
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Post by EmRR on Aug 3, 2015 23:15:55 GMT -6
I think he's a good designer, and has made some interesting classic/modern hybrid products. Looking at the schematic, I understand why he went with that approach. Most of the sound will be the transformers. I reside in the bogs of antiquity, and that design is of a later mindset, so it doesn't really interest me. No reason I can claim it wouldn't interest you though.
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Post by jeromemason on Aug 3, 2015 23:41:20 GMT -6
My thoughts are similar to yours Doug, but I had an idea that since that is a single opamp it might be possible to use a DOA-P-dip. From the sounds of it he might be running close to the edge of current, and space limitations could prevent it, but, if it were possible to place a DOA in there for the price I would think it would sound quite nice. Probably sounds great now, but if a Red dot were able to be fitted inside I'd be willing to take a chance on it. Seems an interesting design nonetheless. I'm mainly looking for a DIY 500 tube pre for vocals and maybe some acoustic overdubs since I am 98% mixing at my place with a few overdubs here and there. I've got a project I'm doing on a female soon, so I am trying to find something I can use as a platform to get a silky and smooth vocal out of. I wish I'd never heard a V76....  |
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Post by gouge on Aug 4, 2015 5:29:14 GMT -6
One option I've been contemplating is using an electro harmonix mic pre as the basis for a diy/mod.
Add some transformers, better power supply, component upgrades.
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Post by keymod on Aug 6, 2015 4:34:55 GMT -6
I have two rack-mount MP66, beautiful pres. Interestingly, the MP66 uses two valves whereas the MP566 has only one. Obviously a space consideration, but I wonder how/if they differ much in sound or performance.
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Post by phrazemaster on Sept 11, 2015 13:40:08 GMT -6
I have an MP66 myself, that I built, and it's lovely!! Can't speak to the rack mount version though. I do have a lot of other gear of his, including his STS (Stereo Tape Simulator) and it's really good too!!
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Post by rowmat on Nov 11, 2015 21:33:21 GMT -6
Hi from a new member.
I built a MP566 a month or so ago and I like it very much.
I was looking for a tube pre that that fell somewhere in between our UA610 MK2 which is too woolly/muddy IMO and a Sebatron Axis 200VU which is very clean unless pushed quite hard.
After assembling and using the MP566 for a while I replaced the supplied JJ 12AT7 with a 50 plus year old Mullard 12AT7/ECC81 and it is definately smoother with the Mullard.
So far I've used it with an AEA R84 ribbon and a Flea 47 on vox and a KM84 on acoustic guitar and it sounds great.
It has good detail without getting clinically forensic and when set to the high gain and pushed it thickens up and becomes nice and rich.
I'm now building a second MP566 and will experiment with a couple of different input transformers.
I initially planned building a MP66 but was informed the MP566 had a little more colour.
NOTE: There has been a revision change from Rev 1.3 to Rev 1.4 which now includes an additional voltage regulator in the tube heater circuit to limit the inrush current when the tube is initially powered up from cold.
Rev 1.3 can be modified to include this extra regulator if required.
It may not be a problem depending on your Lunchbox power supply although if you had a bunch of them in the one Lunchbox then the unmodified Rev 1.3 pres might suck a bit too much current during power up.
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Post by rowmat on Nov 12, 2015 1:51:40 GMT -6
I have two rack-mount MP66, beautiful pres. Interestingly, the MP66 uses two valves whereas the MP566 has only one. Obviously a space consideration, but I wonder how/if they differ much in sound or performance. The single tube is also because of power limitations. From the schematic the output of the single 12AT7 goes through the output level control into an OP134 FET opamp and then into a LT1206 current feedback amplifier that drives the output transformer. I would think this second stage of the circuit (OPA134/LT1206) would be pretty clean with most of the colour being provided by the input transformer and valve, and possibly also the output transformer if driven hard enough by the LT1206. The OEP input transformer in the MP566 won't be as clean as the Lundahl in the MP66 and I doubt if the Edcor output transformer will be as good (on paper) as the Cinemag. It's the subtle imperfections that make it what it is. Pleasing to the ear IMO. Although it has a single valve it's pretty much the tone I was hoping for without costing an arm and two legs. P.S. Regarding your MP66? Can you get some colour/warmth from it or does it remain pretty clean? |
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Post by jeromemason on Nov 12, 2015 13:02:31 GMT -6
I'm building my own 500 Tube pre, but I got a lot of inspiration from their schematic. I suppose it's a combo of this and a Redd.47. I'm going to run two tubes, my rack allocates current as needed per slot, it's possible I may have to settle for a 2U size, although, I've fit it all in a 1U 500. I went with Lundahls on the input and Carnhills on the output, seems like that should balance out to the sound of the Redd.
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Post by rowmat on Nov 12, 2015 16:26:17 GMT -6
I'm building my own 500 Tube pre, but I got a lot of inspiration from their schematic. I suppose it's a combo of this and a Redd.47. I'm going to run two tubes, my rack allocates current as needed per slot, it's possible I may have to settle for a 2U size, although, I've fit it all in a 1U 500. I went with Lundahls on the input and Carnhills on the output, seems like that should balance out to the sound of the Redd. What rack are you using? I have a CAPI 11 slot rack with a dual supply I built which seems excellent so far. I've been considering a Telefunken/TAB V72 or V76 or possible a Mercury V72s/V76 but the cost is putting me off. I'm in search of the holy grail of big, warm, lush, smooth. I'd definately consider building a rack dual channel tube pre if it could achieve the above for up to around $2K. |
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Post by jeromemason on Nov 12, 2015 17:47:10 GMT -6
The Redd.47 is really the only pre I know of that's close to the V7x of Tele. The transformers and plate choke in the V7x's are a big reason of their sound, not to mention just a brilliant design. The good news with that is the Redd.47 came after them, and still has that same signature. It's not totally the same though, but, there are things you can do to find a middle ground. Me going with a clean input transformer and a more colored like a Carnhill on the output is my attempt at trying to get at the sound as well. The circuits are incredibly simple and because of that there are just not many parts, so the cost of recreating or deriving your own design from them is pretty cheap.
With all that said, if you're wanting two channels of REdd.47 and you're ok with 19" rack units, I'd put in an order for 2 from Dizengohff for their D4. Matt is a great designer and from the conversations I've had with him about the D4 it's probably what you're looking for. $1,400 for a pair is pretty damn good.
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Post by rowmat on Nov 12, 2015 21:15:41 GMT -6
The Redd.47 is really the only pre I know of that's close to the V7x of Tele. The transformers and plate choke in the V7x's are a big reason of their sound, not to mention just a brilliant design. The good news with that is the Redd.47 came after them, and still has that same signature. It's not totally the same though, but, there are things you can do to find a middle ground. Me going with a clean input transformer and a more colored like a Carnhill on the output is my attempt at trying to get at the sound as well. The circuits are incredibly simple and because of that there are just not many parts, so the cost of recreating or deriving your own design from them is pretty cheap. With all that said, if you're wanting two channels of REdd.47 and you're ok with 19" rack units, I'd put in an order for 2 from Dizengohff for their D4. Matt is a great designer and from the conversations I've had with him about the D4 it's probably what you're looking for. $1,400 for a pair is pretty damn good. Thanks for that. A local store carries both Mecury and Dizengoff preamps. I'm going to take a few mics in next week and try them out. |
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Post by rowmat on Nov 16, 2015 21:34:11 GMT -6
Just finished the second preamp.
I can now switch between both pres and compare tubes on-the-fly.
The late 1950's Mullard 12AT7 definitely beats the JJ Electronic.
The Mullard has more body, warmer lows, smoother mids and sweeter highs.
Using a KM84 as a reference mic.
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Post by mulmany on Nov 16, 2015 21:51:17 GMT -6
What would you say it's compressive nature is? That's what I love about tube pres, the slight rounding and added harmonics.
Is it in the "wow that's different", or in the "I only hear it when pushed, right before distortion" camp?
Thanks
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Post by rowmat on Nov 17, 2015 1:09:55 GMT -6
What would you say it's compressive nature is? That's what I love about tube pres, the slight rounding and added harmonics. Is it in the "wow that's different", or in the "I only hear it when pushed, right before distortion" camp? Thanks The difference in tubes is noticeable whether pushed or not. With the Mullard, set to the mid gain position (no pad with 27db of negative feedback) the pre is clear and smooth. In the high gain position the negative feedback is reduced to 7db and as you crank the gain further it gets more harmonic and richer in tone. There is some compressive effect for sure. The JJ Electronic tube is brighter in both settings and maybe preferable if you want more 'hair' in the top end than the Mullard but the Mullard is definitely nicer to my ears. Spent a couple of hours with a Flea 47 into the MP566 and then into a JLM LA500 Opto compressor. Backing off from the Flea to about eighteen inches and cranking the gain on the pre was very nice. |
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Post by rowmat on Nov 18, 2015 1:05:48 GMT -6
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Post by mdmitch2 on Jan 24, 2017 22:33:07 GMT -6
Are you still liking these pre's? Did you ever try different transformers? |
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Post by rowmat on Jan 25, 2017 6:36:03 GMT -6
Are you still liking these pre's? Did you ever try different transformers? Not yet as I've been building a bunch of other stuff. Still using the MP566's and still liking them. Although I did recently purchase a pair of NOS 12AT7's from Bowie and have been using those in the pre's. Also one of the DC-DC convertors that supplies the 225 volts to the tube failed. I contacted Jean-Pierre at Sound Skulptor and he was kind enough to send me a replacement free of charge which has been working fine ever since. I may still get around to trying another transformer although after comparing the MP566 with our Sebatron Axis 200 (cleanish tube pre) and our Mercury Bruder V72/V76 (more colored) I think the MP566 kind of falls somewhere in between which I actually like. It's great with the Flea 47 on Vox and a KM84 on acoustic. |
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Post by mdmitch2 on Jan 25, 2017 10:29:38 GMT -6
Thanks for the info --- I'll have to try one of these out. Or maybe I'll wait for a viable redd 47 project. Seems like the drip version is a bit of a nightmare since they dropped their forum.
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