OP-AMPS 

Better power shows promise for the controversial opamp. Throughout the year we have made substantial gains in resolution and have been surprised by the performance of audio grade opamp. Previously, we strongly believed that discrete transistors and tubes were the optimal way to listen regarding Cd player output stages. Presently, as our mains quality improved and battery power supplies has been in the R&D department we have heard some fantastic sound with the standard opamp. It is common to hear a slight compression and a lack of "pulp factor" with opamps while going to a discrete or tube stage always seemed to correct this problem giving warmth, palpability, and ambience…simply more real sounding. Well, things change and we are not ashamed to admit we were wrong. We now believe the sound of an opamp is absolutely diminished or complemented by the quality of the power it is fed. With heavily corrected mains we hear stunning resolution and musicality much the opposite of our previous evaluations. Going to batteries, could be even more advantageous as now the opamp is not affected by our mains in any way. This confirmed two issues for us: First, audio opamps are actually superb sounding. Second, power is everything.
We sell a selection of the finest parts and ready made gear in hi-end audio from Audio Consulting, Audiocom, Mantra Sound, Eichmann, Bybee, Jensen, and Blackgate.
AD825 Module Type 1, Single AD825, 8 Pin/DIL, 11/16"L x 1/2"W x 9/16"H	AD825 Module Type 1, Single AD825, 8 Pin/DIL, 11/16"L x 1/2"W x 9/16"H Check Latest Price Configuration: 1 AD825 Op-amp, 8 Pin/DIL Dimensions (L x W x H): 11/16" x 1/2" x 9/16" ...
AD825 Module Type 2, Dual AD825, 8 Pin/DIL, 11/16"L x 5/8"W x 9/16"H	AD825 Module Type 2, Dual AD825, 8 Pin/DIL, 11/16"L x 5/8"W x 9/16"H Check Latest Price Configuration: 2 AD825 Op-amps, 8 Pin/DIL Dimensions (L x W x H): 11/16" x 5/8" x 9/16" ...
AD825 Module Type 3, Single AD825, 8 Pin/SIL, 15/16"L x 1/4"W x 7/8"H	AD825 Module Type 3, Single AD825, 8 Pin/SIL, 15/16"L x 1/4"W x 7/8"H Check Latest Price Configuration: 1 AD825 Op-amps, 8 Pin/SIL Dimensions (L x W x H): 15/16" x 1/4" x 7/8" ...
OPA627 Module, Dual OPA627, 8 Pin/DIL, 11/16"L x 5/8"W x 9/16"H	OPA627 Module, Dual OPA627, 8 Pin/DIL, 11/16"L x 5/8"W x 9/16"H Check Latest Price Configuration: 2 OPA627 Op-amps, 8 Pin/DIL Dimensions (L x W x H): 11/16" x 5/8" x 9/16" ...
With most CD players, the analogue output stage is driven by operational amplifiers. This is true of entry level models, to the more expensive high-end machines. The op-amps used are generally of poor quality, corrupting the analogue signal, having a disastrous effect on the sonic capabilities of the CD player. The effects are a smearing of detail, reduced dynamics, congestion of instruments on complex music passages causing a mass of sound, rather than a spacious, airy, sound stage. The quality of the mid-high frequencies is particularly poor, where the mid-band is brittle and aggressive, and higher frequencies are edgy, cold and fatiguing to listen to. The following op-amps produce the poorest results; NE5534, NJM2114, NE5532, NJM4558, NJM4560, AD711, AD712, LM833. The performance of op-amps from different manufacturers varies considerably. Therefore, selecting a single type of op-amp to meet the parameters required for the analogue output stage involved analysing data sheets and conducting many listening tests. The important parameters for sound quality are high speed (or bandwidth) low THD, fast settling, and low input noise. The most natural and musical sounding were FET-Input types as opposed to bipolar. The characteristics of the Analog Device AD825 gave the most consistent results with multi-bit, bitstream and hybrid machines. The AD825 is a high-speed J-FET amplifier, only available in a surface mount (SMD) package. We have developed a small PCB module to carry it in the more popular Single In Line (SIL), and Dual In Line (DIL) packages. The module is built using Black Gate BG-NX Hi-Q power supply de-coupling capacitors for their superb noise damping and sonic properties. Gold plated, Beryllium Copper pins complete the design. There are 3 different types of module available; Type 1 -DIL/8-Pin - Single op-amp replaces NJM5534, NE5534, OPA134, OPA132, AD711, AD847, OPA604, LF356, LM318. Type 2 -DIL/8-Pin - Dual op-amp replaces NJM5532, NE5532, LM318, OPA2134, NJM2114, NJM4558, NJM4560, OPA2132, AD712, AD827, OPA2604, LF353. Type 3 -SIL/8-Pin - Dual op-amp, specially for use in TEAC VRDS10, VRDS10SE, VRDS25. Reviews David Robinson of Positive Feedback