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Post by bluegrassdan on Apr 15, 2017 22:45:43 GMT -6
Here is the latest front panel design of my tube pre. Any thoughts or suggestions?
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Post by bluegrassdan on Apr 12, 2017 10:55:36 GMT -6
Will probably offer a NOS tube upgrade for $400. GE 5-star 6072As and Telefunken smooth plate ECC82s.
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Post by bluegrassdan on Apr 12, 2017 10:49:25 GMT -6
Probably in the $1,800-$2,000 neighborhood. Not entirely sure yet.
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Post by bluegrassdan on Apr 12, 2017 10:18:21 GMT -6
Thought I might share these videos of my second prototype. I plan to build about 10 or so of these two-channel tube mic preamps for sale. Still working on the front panel design, but curious to know if there is enough interest first.
Here is a brief sample taken with an iPhone video, demonstrating the DI circuit and low shelf filters. The audio quality is poorly captured, but it was funny to see the visual effects in the iPhone's vibration on the stand. More samples to follow.
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Post by bluegrassdan on Mar 20, 2017 22:08:26 GMT -6
I also used it with APIs, Vintechs, Grace, a few consoles, etc. It's a dark mic. Glorious mic.
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Post by bluegrassdan on Mar 20, 2017 20:13:44 GMT -6
I added quite a bit of high shelf for that video. Listen closely and you'll hear some noise. Curious - What preamp did you use? Hmmm. I don't quite remember. Probably the SCA C84 (Millennia style) I built for it. Probably used a Cloudlifter too.
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Post by bluegrassdan on Mar 20, 2017 20:11:09 GMT -6
Hey guys, My tube preamp design is going well. I'm at the point of designing the faceplate and could use some opinions. Let me know which color you prefer, and if you have any advice on the overall design. Choices are yellow, tan, olive, green, and blue. (Or if you think they all look bad, please say so.) Attachments:
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Post by bluegrassdan on Mar 19, 2017 9:48:29 GMT -6
I added quite a bit of high shelf for that video. Listen closely and you'll hear some noise.
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Post by bluegrassdan on Mar 19, 2017 9:45:38 GMT -6
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Post by bluegrassdan on Mar 19, 2017 9:44:16 GMT -6
It's like Drbill said above. Nothing else does what a 44 does. It can make a thin vocal sound like the voice of God from 3 feet away, but you'll need some eq to give it some brightness. Even then, the brightness you EQ in can be kind of metallic and not smooth like a good LDC.
Another problem with the originals is how they pick up RF noise and other stray interference. There were times when I couldn't use mine at all due to the inherent design flaw. Even our AEA has this problem, and the old timers can be really bad and unusable in certain locations.
You might look at the AEA version with the preamp built in. Haven't used it, but I suspect it may help in this regard.
I sold mine for a Flea 47 and do not regret it. I may own one again, but only after I add a few more condensers to my locker.
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Post by bluegrassdan on Mar 18, 2017 23:44:40 GMT -6
Had one and sold it.
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Post by bluegrassdan on Mar 7, 2017 10:11:51 GMT -6
Like fiddles, banjos vary so much from instrument to instrument and player to player. I definitely lean toward faster preamps like Grace in most situations.
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Post by bluegrassdan on Mar 6, 2017 22:55:53 GMT -6
Lots of folks have questions about recording bluegrass banjo, so here's a short example of my approach. I bet Randy and others have some additional techniques they use depending on what they're after.
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Post by bluegrassdan on Mar 1, 2017 20:11:16 GMT -6
The AML compressor is also very interesting. Kinda want a couple of those too.
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Post by bluegrassdan on Mar 1, 2017 20:07:01 GMT -6
The AML one-space kit cost me exactly $890.04 to build, including the case and everything. I'd say that's more than reasonable considering the Heritage stuff goes for upwards of $2200. You can buy the pre-built two space 500-series for right around a grand.
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Post by bluegrassdan on Feb 28, 2017 21:03:40 GMT -6
We have ABed the AML ez1073 against the Vintech (I may have even put that on here - don't remember). The Vintech is fine, but on vocals it does this weird "pinched" thing in the upper mids. Not sure how else to describe it, other than it fatigues my ears whereas the AML does not. It's smooth as butter.
Don't know how it compares to a vintage Neve. Kinda don't really care either! It sounds great on every vocal with every mic I've run through it so far.
Dialing in the tube pre for my guitar has been a fun project. Need to try it on some other instruments now like upright bass, mandolin, banjo. I doubt it will be a go-to fiddle preamp, but you never know. There might be a fiddle out there that could be well matched to it.
I've been considering building one more for myself, and possibly one more to sell to help recoup some costs.
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Post by bluegrassdan on Feb 28, 2017 17:58:27 GMT -6
What I found really interesting is the sound of the vocal with the tube pre is a kind of sound I try to dial out when I'm mixing, it's a bit forward, and felt a little unbalanced, maybe needing some kind of compression or automation to even it out. I felt none of that with the Neve. Colin's ez1073 is so incredible for vocals, and the EQ is very useful when tracking.
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Post by bluegrassdan on Feb 28, 2017 1:46:39 GMT -6
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Post by bluegrassdan on Feb 28, 2017 1:44:29 GMT -6
Here is the "final" final video. This speaks to what many of you pointed out in your comments, and what I perceived during the design. The tube preamp on guitar is a bit mushy in the low frequencies, so I incorporated a couple of three-position switches with two different low shelving RC networks between the first and second gain stages. The result is not just a gentle decrease in the low frequencies, but also a tightening up of the phase relationship and punchier transients due to resistive loading between the gain stages. I think that the Tube pre with low shelf on guitar along with the 1073 vocal wins the prize. What say you?
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Post by bluegrassdan on Feb 27, 2017 21:37:22 GMT -6
Thanks so much for all the input. I'm going to add one more video shortly. I built into the tube preamp a three position switch: one flat and two gentle low shelves that roll off some of the mud and tighten things up. They are not high pass filters, but honest to goodness shelves that maintain the low frequency info.
Should have it recorded in a couple hours. Stay tuned!
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Post by bluegrassdan on Feb 26, 2017 23:34:10 GMT -6
Chase,
Thanks for the detailed response. The 19" AML is offered as a kit WITHOUT a case, IEC inlet, or knobs. Dan at collectivecases.com supplies the case and knobs are, indeed, Marconi. His 1073s are vocal recording champs!
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Post by bluegrassdan on Feb 26, 2017 16:26:37 GMT -6
Thanks so much, guys. The verb is Altiverb, although I don't remember what settings were used. I can go back and check.
The tube pre began when I read Scott Hampton's article in Tape Op, which provides a schematic and multi-page description. After starting into it though, several things changed; component values, adding components, removing, using a totally different PSU.
I also added a switch with two low shelf filter settings (not high pass, but gentle shelves). These really tighten up the low end that folks here were describing as being too loose. Maybe I'll post another sample with the filters engaged, but for now I kept it flat.
Keep em coming!
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Post by bluegrassdan on Feb 26, 2017 10:53:03 GMT -6
Hey folks, Here is a video sample of a comparison between my hand-built AML ez1073 preamps and a two-channel point-to-point tube preamp I finished this week. Using my Flea 47 [EF12 tube, F7 (M7) capsule] on vocals, Flea U47 on guitar (left) and Neumann KM84 (right). Curious to know everyone's thoughts. Which do you prefer in this setting? Thanks in advance! Pro Tools session available here (24/96k): www.dropbox.com/sh/5nc613f7ymeefvt/AADTgpkZ66fQWqW9tRdpUc-Ia?dl=0
And one more video demonstrating the low shelf filter:
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Post by bluegrassdan on Feb 17, 2017 7:29:54 GMT -6
Okay guys, I'm euphoric! I have been tweaking and adjusting like crazy on my DIY two-channel tube preamp. Finally landed on the prefect RC network to make it sing!
My goal was to build a tube pre that would match my Sumi dreadnought guitar and pair of KM84s. Something that I can carry into any studio and it will sound like me.
So, here it is. My guitar, mics, and preamp. No compression, EQ, or reverb. Just the basics. I'm flying high!
Please let me know your thoughts.
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Post by bluegrassdan on Feb 10, 2017 16:23:44 GMT -6
The schematic is based on Scott Hampton's tube preamp from a 2002 tapeop article. I made a few minor tweaks to the design. The PSU regulator pcb kit is from here: glass-ware.stores.yahoo.net/hiposu.html
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