The Steel Guitar Forum

Given that I'm not gigging much (i.e. any), I've been spending a lot of time organizing my studio, and doing some research on gear updates, etc.

I recently installed a 500 series rack, primarily to expand my preamp selection, and that (and a friend's gentle nudge) got me turned onto the whole DIY market. Once I went down that path, I found out that if you're reasonably good with a soldering iron and standard electronic bench gear, you can build a really good preamp (and other recording gear) for a lot less than the same thing would cost you already assembled.

In my case, I was looking for some options for a preamp from the 'color' family. Rather than just clean gain, this family of preamps has an inherent 'sound' that is usually described as 'warm' or 'fat', and is often associated with vintage API or Neve consoles. These are the consoles a lot of hit records in the 70's and 80's were recorded through. One common trait of these preamps (or console channels) is discrete components and transformers. No ICs are typically found in the audio path, even the OpAmps are discrete, built with transistors. So, they are actually good candidates for DIY kits.

Once I started looking, I found this webpage, which is a company owned and operated by an API guru. I've read that he actually has a vintage API console in his basement (it was so big it had to be disassembled to get it down there), and he has used that to reverse engineer and recreate that API sound in a series of different 500 format preamps.

Classic Audio Products

So I got interested and ordered a couple of API 'clones' to check it out. This is what showed up (one kit, check the input and honking output transformers ):



I worked slowly, a few hours over a couple of nights, but had no problems with the build. There's a lot of build guide information available. The kit also includes the discrete op amp, which was a little more challenging, only because the board is compact about 1.5" square.



I put the first one in the rack, it powered up perfectly, and I'm really happy with the way it sounds. These particular pres have an input gain and output attenuator, so you can drive the gain stage a little harder to get more or less of the 'color' and then attenuate the output down to whatever level your interface needs. The second kit has since been built and installed next to this one. It went considerably quicker.



This DIY project went so well, I'm on to the next one. These guys out in Seattle offer an 1176 blackface FET comp 'clone' in a 500 series format. This kit has a few more parts, and some post assembly calibration required, but I'm confident this will be a great addition to the gear 'stable':

https://www.hairballaudio.com/catalog/f ... revision-d



Anybody else build DIY stuff? Any hot tips on cool products? Doesn't have to be recording gear, I've seen some pretty cool guitar effects etc.

The CAPI stuff is the real deal!! Not having the op amp expoxied makes them run cooler and last longer than the API ones, too. Great stuff, as is Hairball!

PS-build one of the 550 eqs to go with that preamp!

Just completed my first tube amp kit build. It is a Trinity "Tramp" Class A 12 watt head. It sounds very good with a classic warm Class A sound with a lot of harmonics. It also has a tube driven FX loop.

Thanks for the lead on the preamps! I will be looking at that next.

I know a couple studios that rave about these:

https://www.seventhcircleaudio.com/

The N72 looks great. I was going to buy them pre made but they are not 500 rack modules.

John wrote:The CAPI stuff is the real deal!!

Absolutely, and Jeff Steiger, the owner has been really responsive with a bunch of questions about which pre, etc.. I'm looking at that EQ already. He also offers another DOA or two as kits, and they swap in and out via an industry standard socket. Gives you a little bit of flexibility, but I'm totally happy so far with Jeff's version.

Dan wrote:Just completed my first tube amp kit build.

Yeah, I'd like to do something like that myself, but I'm afraid I'm too klutzy to be around that B+. haha.. I'll bet it sounds great.

Bob wrote:I know a couple studios that rave about these:

https://www.seventhcircleaudio.com/

The N72 looks great. I was going to buy them pre made but they are not 500 rack modules.

Tommy D. has some, he likes them a lot, but I'm sorta slowed by the 'not 500 compatible' part. We figure the new owner has to be considering moving to that format eventually... or not. But they DO get rave reviews.

These are tempting! I've built some pedals in the past, and have a background in shipboard comms so they're 100% doable. Now I just need to come up with a reason... Just how big a difference is it doing these functions with outboard equipment? Currently I do everything in my DAW (Ardour on Linux) and it's perfectly fine. But I sure do miss twiddling actual knobs.

Jim wrote:Just how big a difference is it doing these functions with outboard equipment?

It's still just routing audio around, but like you mentioned, I miss having knobs to turn, and I think that's a lot of the appeal for most folks.

I can't speak for the 'workflow' for guys like John Macy, and the real pros, but for me, these preamps are just part of the chain, before going into the interface and on to the DAW. I like to 'print' with the preamp sound there already, and it's just a way to get the sound you want, right from the get go. It's really sort of old school if you think about it.

As for processing already recorded tracks, that's still doable by most every DAW I've seen, you have to set up an input/output pair and route the signal out and then back in. It's just as an insert in the channel (or mix bus), at least that's how I do it. No doubt there are other ways.

Of course your interface dictates to some degree what you can and can't do, i.e. you may find you need more input and outputs. I have an older 12 x 12 Echo Audio interface, no integrated preamps, it's all just line-ins and line-outs, and it's a piece of cake to route via Studio One.

The downside to outboard stuff is that if you have to recreate a setup, it's not all saved as part of your DAW project. You have to take photos, or write settings down so you can set all the controls back like they were for round two. The convenience of plugins is really great, but I like the idea (and sound) of real hardware as well.

I'd be interested in hearing how the real engineers use this stuff.. maybe John or some of the guys that do this for a living will chime in.

I went the hybrid route for a couple reasons. I got my first real compressor to help learn how this stuff really works without using my eyes. As I got more work and dug in deeper I kept hearing more. I got better speakers and did some room treatment and heard way more than I knew was there. In the box is great and I may end up there at some point. But when I compare an actual Pultec with a plug in or hardware knock off I get it. It's like that Emmons PP problem. You can't unhear it. We are talking about very small nuances here. Plug ins are amazing and practical but don't impart the same visceral experience when I listen to them. Today I was screwing around with a string bass part for a chamber music thing Dave Biller wrote. I used a Pendulum Audio ES-8 limiter and was able to move the bass into the room with the other players and shape the notes into perfect warm little pillows. Without any destruction or modification of the players sound. The real hardware stuff is pretty awesome.

As I got more work and dug in deeper I kept hearing more. I got better speakers and did some room treatment and heard way more than I knew was there. In the box is great and I may end up there at some point. But when I compare an actual Pultec with a plug in or hardware knock off I get it. It's like that Emmons PP problem. You can't unhear it. We are talking about very small nuances here.

Yeah, that's sort of been my experience as well, especially the 'You can't unhear it.' part... except I don't own a Pultec EQ.

I've got that Hairball FET Comp in the rack now and it's killer, really enjoy tweaking knobs and it's definitely got the 1176 vibe in spades, complete with the bass-ackwards attack and release knobs.

I do have one warning to anyone planning to use hardware processing with a DAW (any novices like me that is). Studio One has a really genius-grade plug that is essentially an extension of the audio I/O hardware manager. You add this 'Pipeline' plug to the channel, and set up the input and output to the hardware from right there. It automatically calibrates the latency for you, and also provides a 'scratchpad' in the plug, to note the hardware settings, or even a photo of the faceplate.

I noticed that between a couple of mix sessions on one song, the system changed enough that I was hearing a slight 'flange' on that channel, caused by a small change in the latency of the return from the the hardware. One click on the Auto button in the pipeline plug and it was fixed. I guess you might have to watch for that in the course of a mix, but it was easy to fix..

I wonder how the other DAWs deal with that? Is it that easy?

I used to enjoy building PAIA stuff like the Fat Man synth, etc. Back in the day, engineers could repair the equipment in their studios, as quite a few got their start with radios, etc. I don’t how true that is today.

Personally, I have accepted an all digital ‘in the box’ studio. I cannot possibly let myself fall into another gear pursuit, as would most likely be the case. But I do love the hardware.

I love working with a hybrid setup and love working in ProTools (I do about 10% of my projects on tape, usually at the client's request). For me, if you get it right on the way in via the right hardware, it makes in the box work pretty well. I like having lots of color choices, hence a fairly large collection of preamps ranging from 1960's tube Telefunken's to modern "wire with gain" pres and a lot in-between. While I could live forever with an API pre and EQ and an 1176, it's nice to have a palette to paint with lots of colors. Same with compressors, lots of choices.

I also like getting it inside correctly, cause if you add a piece of analog gear as an insert later, it has to go through another D/A conversion and another A/D conversion coming back in. I do like to mix through a console so all the digital outs only get converted once and the analog processing is done in the analog mode.

ProTools has a universal delay compensation that does all the tracks at once, both for plugin delays and also for analog inserts.

All that said, I feel I have mastered how to mix "in the box" pretty well. There are some ways to do it that get's very close!

A few years ago, I bought some "pro audio" CD-ROM off ebay that had over 750 schematics, supposedly of boutique audio equipment – Pultec, API, Neve, Urei, Focusrite, etc. I bet that a lot of them are legit, but probably not all.

I have a friend who worked for API in Springfield, Virginia in the '80s and '90s, and he said that the schematic for the 2520 op amp was not legit. The guts of that thing were proprietary, and potted in epoxy that would destroy everything if you tried to extract the circuit.



Yeah, it's a fantasy to build your own high-end stuff...but I don't have the time or patience. Also, I don't think I have test and calibration procedures for all of the stuff on that CD-ROM.

John wrote:if you get it right on the way in via the right hardware, it makes in the box work pretty well.

That's kind of the approach I'm trying to use with all these kits. So do you mix through a console a fair bit?? What do you have?

Duane wrote: The guts of that thing were proprietary, and potted in epoxy that would destroy everything if you tried to extract the circuit.

Yeah, I've read that too.. Supposedly, some 'un-epoxied' examples from 'unofficial' sources have escaped a time or two, but I wouldn't swear to it. Buildable/authentic or not, I'll bet that CD had some interesting stuff in it?

I have always had large format consoles over the years, but I went to a smaller, more hybrid setup last year with an API Box console. It has four channels with API eqs (two 550A and two 550B) and sixteen summing channels, which I configure as eight stereo channels for stems from ProTools. All channels have inserts for analog gear, and the mix buss has a built in API buss compressor. There are also four sends per channel. I love this console!

I have an interesting hybrid setup where I duplicate the set up “in the box” in ProTools using plugins, which lets me work offline in my home studios and is easily switched over with the hardware pieces replacing the plugins. It allows me to do a lot of the mix work myself and then finish it at the studio. I also have the in the box mixes getting pretty darn close if needed. At home I still print the final mixes going out through some analog buss compression and a custom transformer box. This setup has been very valuable, especially during the quarantine.

Very cool John! So this one? In my dreams.. LOL

Yep, though they only had the four channel
Version when
I bought mine.

I was hoping you'd share. LOL... So is the lava lamp and Paris rack just out of frame?

I sure do miss Paris, nothing sounded better!

I sure do miss Paris, nothing sounded better!

Me too.. I've stumbled onto a recording or two from that era a while back, and it really did have some mojo.

Bill Terry wrote:I'll bet that CD had some interesting stuff in it?

Ooooooh yeah..

With these kinds of outboard setups, do you really need an expensive patchbay? As long as it's balanced, can you go with cheaper options? Does this really matter? Switchcraft is very expense when compared with Samson or ART or DBX. Will TT sound better than TRS? I don't plan on buying a ton of outboard gear and won't need 96 points.

These are great and not too expensive for small setups. I carry one with my portable rig. Uses db25 connectors on the back so no soldering and premade cables are easy to get.

Thanks John. Is there any difference in sound quality with 1/4" balanced TRS?

John Macy wrote:These are great and not too expensive for small setups. I carry one with my portable rig. Uses db25 connectors on the back so no soldering and premade cables are easy to get.

No difference in audio quality; just necessary for mic inputs, outboard processing, and DI boxes that use balanced outs.

More updates from my latest GAS attack.. (DIY kits)

I bought two of these 500-series Neve 1073 clones from Audio Maintenance a while back. A bit more 'assembly required' than the CAPI kits way up in the original post, but I REALLY like these pre-amps. Like the CAPI pre-amps, there are no op amps, all discrete components and transformers. I was a little reluctant to order from the UK, expecting a potentially long shipping delay, but they arrived very quickly, just a few days after the order. I still don't know how they got it to Texas so fast. If you've ever listened to any record from the early 70's (and later) you've heard these. They were and are a gold standard.

http://www.audiomaintenance.com/acatalo ... _info.html

Finished products:



And I finally got up the nerve to build a tube amp, and this 5E3 clone from Stew-Mac is outstanding. I've got it together now and couldn't be happier. There are several other 5E3 kits that also get good reviews (Mojotone for one), but as a guy who has made a living writing technical documentation, the Stew-Mac build guide is exceptionally good.

https://www.stewmac.com/kits-and-projec ... 5w-amp-kit



Not sure what's next... always looking.