REVIEW AUDIOSCAPE V-COMP+ 6386 DELUXE EDITION, WHAT IS GATES STA-LEVEL?

Original 1950s Gates Sta-Level

The Gates Sta-Level was a vacuum tube compressor/limiter designed in the early 1950’s (like me :-). It used a variable-mu tube to achieve gain reduction (the same remote-cutoff tube type as used in the famous Fairchild compressors).

Now AudioScape in Daytona, Florida has brought the original circuits back to life, complete with “Sonic Truth”, vacuum tube power supply and the all important, “6386”, remote cutoff, variable-mu tube that does all the gain control. I started on this review over a year ago, there were some BIG surprises along the way.

First of all, the "Gates" we’re discussing here never had anything to do with Bill Gates or MicroSoft. 

The older “Gates Radio Company” was heavily associated with radio station equipment and broadcast hardware manufacturing; my electronics mentor Dr. K had an older Gates broadcast console at the heart of his ham radio station in the mid 1960’s. 

The Gates Sta-Level hardware was typically located near the input of a radio station transmitter and was used to reduce the peaks (to prevent over-modulation of the transmitter input) while raising the low level signals so that a broadcast had a nice even sound to the listeners with minimal noise.

My first "V-Comp+ Deluxe 6386 Edition" by Audio-Scape

AudioScape calls their version (of the classic Gates Sta-Level) “The V-Comp + Deluxe 6386 Edition”; the 6386 refers to the vacuum tube used to control the volume level passing through. This unique part was discontinued years ago and the only replacements have been new-old-stock, with the price of these rising past $250 each for premium pieces. JJ Tubes has created a new 6386 tube which is breathing life back into the variable-mu designs of yesteryear. Devotion to authenticity is what leads to “Sonic-Truth”, that is what AudioScape promises in their product description. Let’s cut right to the heart of this, AudioScape has figured out how to use the new JJ 6386 and has built an amazing sounding tube processor. 

AUDIOSCAPE V-COMP+ DELUXE 6386 EDITION

Note: This is the model we’ll be discussing, hereafter I’ll refer to it simply as V-Comp but you’ll understand I’m not talking about any older models previously produced by AudioScape.

I ordered my first V-Comp because I was fascinated with variable-mu style compressor limiters. It took almost a month for my order to arrive and I was anxious to put it into service. I had a lot of fun trying it as a mixing tool. I channel patched it onto the lead vocal track and it had a pleasant character but something kept nagging at me; what would the V-Comp sound like in stereo, as a bus compressor. To definitively answer this question I ordered a second V-Comp. When the second one arrived I was surprised to see it had a lower serial number than the first one. I chalk this up to the product being built-to-order in very small batches.

Receiving a new AudioScape product has been consistently the same, an oversized shipping box with massive foam insert for shock protection. The V-Comp was no exception, the unit separated from its packaging and was flawless in construction and appearance. It’s a large, 3U rectangular metal box with a transformer hanging off the backside. Input and output jacks are 3-pin Neutrik XLR connectors. I had requested the “link” jack so two V-Comps can be connected together for correct stereo operation (the connection requires a simple unbalanced 1/4” guitar patch cord). Chris, one of the AudioScape owners followed up and told me they are installing the Link jack on all production V-Comp models now. 

SOME RECORDING TECHNIQUES I TRIED

I tried recording vocals “with” V-Comp inserted in my recording chain, since I’d read on several forums that some folks like to record with a Sta-Level. I tried it after a Locomotive Audio tube preamp, I tried it after a Neve preamp, I tried it in the effects insert on the Neve 1073SPX. Finally I recorded with an API 312 preamp feeding the V-Comp and it sounded excellent. I was applying very modest compression and the V-Comp did a nice job of smoothing out the volume level.

Normally I’m not a fan of “tracking” with compression because it invariably seems to get in the way when I start the final mix process, I almost always wish there was no recorded-compression so I can add the appropriate amount during mixdown without working around previously recorded “smoothing”. The V-Comp was no exception, I preferred it as an insert at mixdown more than recording with it. 

My final test-recording adventure found the V-Comp in the insert-loop of a 5150-III 50-watt guitar head. I had this amp connected to a Vintage Marshall 4x12 filled with G12 Celestion speakers. With it cranked up to concert volume this potent combination delivered slide guitar tones that would make Lowell George and David Lindley smile BIG! As a guitar effect the V-Comp has the ability to create almost infinite organic amplifier sustain, with or without preamp distortion effects. Glorious is the only word big enough to describe that tone.

MIXING AND MASTERING

Pair of V-Comps, note blank space, vented panel, above each processor for cooling

Finally I was equipped with two V-Comps, I moved them to a special rack in our studio where a patchbay selects which processors and what order they appear in the Coleman TC-4 mastering processor connected to my Neve mixer outputs. With the Coleman I can switch processors in and out of the signal path, this makes it very easy to hear exactly what is happening from the connected effect gadgets. The Coleman uses relays in an all-passive, analog design which eliminates unnecessary circuits and coloration, this lets you hear with surgical precision.

I have an album project I’ve been working on for almost a year and was anxious to hear the V-Comps in action on the mix. Finally the day arrived, everything was ready, I began mixing and tweaking the V-Comps. You don’t get classic compressor controls like Attack and Release time. The V-Comp threshold is fixed (like an LA-2a); I was tweaking the Output level controls on the V-Comps while pressing the IN/OUT button on the TC-4. By carefully matching the output level(s) it brings focus to what the attached processor is really doing without any distracting volume level mismatches. My first day of mixing was mainly about understanding the controls on the V-Comp and how they alter the output sound. 

The V-Comp sound is unique and a little bit quirky to dial in. A rotary switch labeled “RECOVERY TIME” seems to adjust the Release time. Another rotary switch labeled “MODE” might be compared to Attack time but the controls are not specific like Attack and Release on an 1176 style FET compressor. More importantly, the controls on the V-Comp are interactive; and just to make things interesting AudioScape added an “input drive" switch which can inject +5dB more push (I’m not exactly sure why you would need this unless you had an anemic source signal that lacked sufficient level).

After a few days of mixing I began to get comfortable with the V-Comp(s) as a bus compressor, their effect on a mix was always magnificent and produced huge fatness. Words fail when describing truly wonderful audio effects but let’s just say that compared to some other bus compressors the V-Comps were delivering unique sounds that my ears instantly loved; no unwanted snaps, no weird breathing, totally musical with thickness and warmth others allude to but but don’t or can’t deliver. 

DISTORTION STRIKES

I was experimenting with the V-Comp controls, trying to understand if there were useful distortion effects available through the adjustments, suddenly I realized there was a lot of distortion and I could not get rid of it. After another hour of experimenting I decided something was wrong; the left channel was worse but both channels seemed to be making what could only be described as “farting” sounds on peaks. 

AUDIOSCAPE REPAIR DEPARTMENT TO THE RESCUE

I sent an email off to AudioScape and before the day was done I had a response and some diagnostic questions. We exchanged another email or two and I was told they would send a replacement tube set. In a couple of days a small box of tubes arrived, AudioScape provided a complete set of everything except for the weird regulator tube (rarely ever fails) and the new 6386 which currently retails for around $200 each. 

Tubes L to R: 6V6, 6V6, 6201 (aka 12AT7WA), JJ 6386, AN5726, OB2, 5Y3GT/6087 TAD (rectifier)

Note: There are three transformers inside the box and one on the rear (not shown)

To replace the tubes you remove the top cover, this reveals the main circuit board and the full array of seven vacuum tubes. 60+ years of repairing tube guitar amps made me suspect the 6201 (aka 12AT7) so that was the first tube I replaced. Now the cover was off and I could see the tubes when the unit was all powered up. After installing the replacement tube the distortion was still there and when I went to look inside I could clearly see one of the two 6V6 power tubes was glowing in a non-standard, bad way. I immediately shut down and replaced the faulty 6V6 with one of the replacements AudioScape sent. I reverted back to the original 6201 and all was well with the V-Comp, distortion was gone and mixing happiness returned. 

Ultimately nobody likes faulty gadgets, problems or repairs but in less than a week Audio-Scape responded multiple times, delivered a comprehensive solution (NOS tubes are not cheap) and got my setup back up and running. Service does not get better than that. 

V-COMP BUILD AND CONSTRUCTION

The construction of the V-Comp units follows classic AudioScape build quality. The metal formed enclosure is a large, 3U rack mountable metal box with vents on the top and sides. All seven of the vacuum tubes are contained inside the enclosure and there is no fan. 

Close up of back-side of front panel input controls

SAFE RACK MOUNTING

Vintage original Sta-Level compressors had the tubes mounted on the rear of the enclosure which moved major heat production to outside the box; this allowed the processors to be stacked in a rack without ventilation spaces between them (provided your rack is well ventilated). I mounted my V-Comps with one blank space between them and an old compressor under the top one to deflect the significant heat coming from the vents of the lower V-Comp. That pair of 6V6 power tubes in a V-Comp generates a tremendous amount of heat and if you block the top vents of the enclosure I can only imagine the bad things that could happen from overheating. 

DON’T STACK THESE DIRECTLY ON TOP OF EACH OTHER. 

The AudioScape front panel may look like the vintage models but the construction is not the same and I think that the ventilation of the V-Comp is barely adequate provided you leave a blank space above each unit. If you block the top vents you’re creating a potential fire hazard. Heat is the biggest enemy of electronics, provide adequate ventilation to your gear and you’ll be amazed how long it will last.

Note: filler panel above each V-Comp for cooling, rear of this rack is open for max airflow

BUS COMPRESSORS COMPARED

I have a few bus compressors which I love to experiment with. The classic SSL bus comp is a favorite for quick leveling adjustments. Other models I have for bus compression include the AudioScape version of the SSL style, the Warm Audio Bus Comp (an SSL style comp with big output transformers), Neve 33609N, API 2500, and the Drawmer 1978. None of these have touched the stereo bus since the fully functional pair of V-Comps moved into the mastering rack. The big rich sound of the V-Comps is like comparing the difference between a solid state guitar combo amp with an eight-inch speaker and a magical old 100 watt Marshall stack; one sounds thin and small (by comparison) and the other is awesome, beautiful and sounds huge. The V-Comps deliver thickness and musical magic that none of the bus compressors provide. I’m not ready to bite off the tube maintenance complexity of a Fairchild but the V-Comps strongly hint why those beastly variable-mu compressors sounded so great on old Beatles recordings. 

The V-Comps sound relaxed but according to my console metering they deliver surprisingly powerful punch. When adjusted wrong the V-Comp can wallow in slow release and twisted dynamics; this is not a set it and forget it piece of hardware when it’s on the bus. When the V-Comp controls are matched correctly to the song dynamics the sound is massive and totally musical; pressing the in/out button on the Coleman TC-4 mastering box confirms, it just sounds richer, fuller, and better with the V-Comp. 

VCA, OPTO, FET, VARIABLE MU

The role of a compressor is to control the loudness of the signals you’re passing through it and there are several different electronic devices that can be used to adjust level. Some of the jargon names are VCA, Opto, and FET; these are just a few of the most popular designs. Variable Mu is the only one of these technologies that actually uses a vacuum tube to do the attenuating and it produces a different sonic signature from any of  the others. If the others involve tubes in their hardware (like the LA-2) the function of the tubes has to do with deriving control voltages or driving the output transformer to warm, soften or boost the signal level.

A big problem with variable gain tube designs is the availability of variable-mu tubes (technically these tubes are referred to as “remote cutoff”); most were discontinued years ago and as the world’s stash of New-Old-Stock is used up the price-each for a replacement tube goes up, up, UP!

AVAILABLE VARIABLE GAIN TUBE DESIGNS

Locomotive Audio in St Louis offers a couple of Variable Mu tube compressor designs (I bought one of each) but they chose discontinued tube types that are still reasonably priced (under $50 each). Retro in California builds a replica of the original Sta-Level but they don’t use the 6386 tube for level control although they do provide an alternative path for you to add one at your own expense ($200 to $300/tube on top of the $3200+ new hardware cost per channel). Chandler also offers some variable mu designs with street prices starting at $2800/channel. With these kind of prices it’s easy to see why Variable Mu designs have fallen from popularity.  

The price of $200 for a single new JJ 6386 seems high at first but according to Chris at AudioScape they have been reliable and I can attest to their quality sound. Another way to look at the JJ6386 is to think of it as the original integrated circuit design contained in a glass bottle; audio goes in, audio comes out and a detector input provides variable gain control; that’s a huge oversimplification but it gives you the basic functional idea of what makes these unique sounding variable gain compressor/limiters so special. If $200 seems like a lot for a single tube, consider that the metals inside a tube are toxic to handle, a bottle of dangerous molten glass is assembled around the toxic metal plates and a vacuum is pulled before the bottle is sealed. It’s such a weird process that the market can only support one manufacturer right now; and thank goodness the good folks at JJ decided to do it. 

JJ 6386, today priced at $184.95 on Tube Depot (they also have NOS starting at $249.95)

LIKES

Straight forward, 3U, rack-mount hardware design

All tube variable mu implementation of original early 1950’s circuit design

True to the original circuit, complete with 6386 tube

Hand built in Daytona, Florida, USA

New Old Stock components

Awesome sound for bargain factory-direct purchase price

DISLIKES

Barely adequate ventilation for seven tubes inside the box

No operating instructions

No cautionary statement about stacking/mounting

EPILOGUE

I have become a big fan of AudioScape and their products. The company is small and nimble while the folks working there have an incredible shine in their eyes; clearly they enjoy what they’re doing. When one of my V-Comps had a technical difficulty they instantly rose to the occasion with a winning solution that restored operation. Going through the repair dance gave me a chance to carefully review the inside and the construction; it’s top notch including thick fiberglass circuit board material, old-school through-hole component mounting and quality transformers.

The sound is the real reason for all this devotion and the V-Comp does not disappoint. Sterile and thin would never be words you would use to describe what a pair of V-Comp are capable of as a bus compressor. I had them up against the Neve 33609 with it’s vaunted diode-bridge technology; when I A-B compare the Neve and the V-Comp it makes me wonder what all that extra fatness is that comes out of the V-Comp, it’s just bigger and richer sounding going through the V-Comps. The Drawmer 1978 and SSL style bus comps sounded even more anemic and light when compared to the V-Comps using the Coleman Transfer Console relay bypass modes. And, just to keep things interesting I had a new pair of AudioScape Pultec-style EQP tube equalizers patched to the Coleman so I could bring in a little bit extra vacuum tube fatness to the sound and judge how that could affect the results (the full EQP story is coming in a future High on Technology review).

At roughly $1500 each the AudioScape V-Comp+ Deluxe 6386 Edition is not exactly cheap. I just checked Reverb.com and there is one vintage Gates Sta-Level available for $5995 along with over a dozen of the Retro branded Sta-Level clones for $2700-$3600 depending on the tubes installed and age of the unit. When you buy from Audio-Scape you get the real deal, the original circuit design that made the original hardware sound so good along with a carefully curated collection of NOS vacuum tubes and a new product, 2-year warranty. I get to own a pair of these amazing processors for about the same cost as one of the big brands from a dealer. In the final analysis I was not crazy about the V-Comp for processing on individual tracks but as a bus compressor the pair from AudioScape delivered a bus mixing surprise I was not expecting. WoW! I love the V-Comp+ DELUXE 6386 Edition, bus compressors. When you think about it that is what they were designed to do, level out the mix bus for radio stations. 

AudioScape delivers the real, big, vacuum-tube sound for an extremely fair price, factory direct to you. 

Thanks for reading High on Technology, Good Music To You!

© Nov 2024 by Mark King. It’s not ok to copy or quote without written permission. 

DIG DEEPER: Here is a link to the H.o.T. review of the Coleman TC-4 

Locomotive Audio reviews on H.o.T. Locomotive Audio

Explore AudioScape: https://www.audio-scape.com/

From AudioScape web site, November 2024