The Amazing Universal Audio 175 B - Extremely Rare and hard to find. My best estimate on age is around 1964. The back of the VU meter is stamped Feb. 7 1964. This is a working unit. It is a vintage product, and I will do my best to fully describe it. It is being sold "AS IS", and returns will not be accepted. The unit is fitted with XLR "pig tails" in the rear for connections. The UA 175B did have double tip input jacks in the front. These were not standard jack inputs, and they have been removed on this unit. Since these were not used, it in no way affects the sound or performance of the Compressor. The UA 175B is a Vari-Mu compressor, and it is very musical. It really is like a wall when cranked up, but sounds like no other compressor I've ever used. It is simply amazing on everything I have used it on. I will try to upload some video's. Unbelievable on Vocals, Bass, Drums, Acoustic, Electric Guitar - ANYTHING! I have recently replaced the Output tube with a NOS 12BH7 Westinghouse tube, and it sounds great. I would absolutely love to keep this. It's going to kill me to part with it. I have to be realistic, I record at home, and though I have some real nice gear - I also have some real nice debt. The unit has been well loved, and always racked. It has not needed much in the way of service. The last I can see it has been serviced was on 1/4/2000, by James Gangwer. He rebuilt the power supply, changed the power cord, and rebuilt the lower circuit board. He has left his service stickers inside. At some point, someone made a cover for this unit. I do not use it, but it will be included in the sale. I would imagine that it is one of the reasons that this unit has fared so well over the years. There were a few pilot holes drilled in the top corners to secure it. I do not have the screws, but could surely find some. It was originally taped on when I got it. I will include pictures of every angle. This is used in a smoke free home recording studio. It has been extremely well loved. The pride of my rack. My favorite vocal chain is from my Neve 1073 or API Pre into the UA 175B, into an 1176. Any of my Neumanns or Ribbon mics, depending on the source. Bass, direct out from My Aguilar into the UA 175B You're starting to get the idea. Over the last year or two, I have watched the market on these. There are usually no more than 1-3 available. 1-2 on Vintage King for $8-9k, and 1-2 on Reverb for about the same. I am listing this at $5895.00 I feel this is a very fair price and will allow for room to have the unit fully serviced by a professional of their choice, if one desires. I can make some recommendations if needed. I can discuss shipping with the buyer, I would pull and individually wrap the tubes. I would prefer to ship next day air, fully insured, but this can be negotiable.
The Universal Audio 175 and 176 compressors were the brainchild of the legendary Bill Putnam Sr., whose genius spawned several products that were initially used in his Universal Recording studios in Chicago and LA, and later became commercially available. The original console in Chicago utilized the famous 108 tube pre-amp, which in turn spawned the 175 and 176 models of tube compressor, the 610 mic pre, and the 1176. The 175 B is a variable-mu style of compressor, where the gain reduction is achieved by a variable-mu dual triode tube, which reduces gain when the input signal is increased. The 175 B uses a fixed compression ratio of 12:1, with attack time adjustable from 300 to 1000 microseconds and release time adjustable from 27 to 527 milliseconds. Both controls increase the speed as they are turned clockwise, and compression can be shut off using the attack knob. In one respect, the 175 is similar to its cousin the Urei 1176; the Input control sets the Threshold while Output sets the output gain. Both Input and Output gain controls can be set from 0 to 40 dB, and are stepped at intervals of 2dB. Finer settings within these increments are obtained by using the "Vernier" controls.The meter can be switched to view Input, Output, or Gain Reduction (GR). The barrier strip also allows for wiring an external VU meter, which can be set for all functions, or just gain reduction (which allows the internal meter to read input and output level). One reason the 175 B has a unique sound is the way the compressor responds. With signal at the threshold level, the compression ratio is 12:1, but the ratio increases as the signal goes higher above the threshold. It will subtly tame the peaks when hit softly, but behave like a brick wall limiter if it's hit harder. The 175 B was manufactured with Double Tip Input and Output jacks; the original cables for these had two 1/4" jacks at both ends of the cable, (which are not standard phone plugs). These have been replaced with standard XLR pigtails. There are also two screwdriver holes for balancing the unit, while keeping the front panel closed so that the VU meter can be checked during this operation. The front panel is hinged, and drops down to access calibration pots for Gain Reduction Zero, Plate Balance and Cathode Balance, as well as a three-position test switch. The 175 B employs six tubes: 6BC8; 12AX7; 12BH7; 6AL5; OB2; and GZ34, along with UTC output and input transformers. From the original operating instructions: "The Universal Model 175 B is an extremely versatile professional quality peak limiting amplifier designed for use in the recording, broadcasting and motion picture industries, as well as other high quality audio systems. the 175 b is a true limiting amplifier capable of high gain, low distortion, linear amplification at levels below the threshold of limiting and with excellent limiting characteristics and negligible increase in distortion at levels above....The highest quality military type printed circuitry is combined with 1% precision resistors and overrated components throughout to insure maximum performance and reliability."
