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Products

I spend a lot of time building and evaluating basic amplifier concepts with an eye toward producing the highest quality sound with elegantly simple circuits.

There is no such thing as a perfect amplifier, but there is a best amplifier for each type of speaker, music, and listener. Each First Watt piece is a unique design and is “best” in some particular way. They look alike because they all use the same basic chassis and power transformer. On the up side, it makes it easy for me to test ideas and compare different designs with the hardware being a fixed constant.

Looking for tomorrow's faceplate with yesterday's circuits?

You're in the wrong place.



Amplifier Comparison Chart

(Click on the product name in the left column for more information)



Stereo/Mono

Output8 ohm

Output4 ohm

Feed-back

OutputOhms

Input Ohms

Input Bal/SE

Distortion%

NoiseuV

GaindB

Mosfet / Jfet / SIT

SE PP

AvailableNew?


SIT-1

M

10w

8w

N

4

100K

SE

0.6

100

18

S

S

Y


SIT-2

S

10w

8w

N

4

100K

SE

0.6

100

18

S

S

Y


J2

S

25w

13w

Y

0.4

100k

Both

0.03

100

20

J

S

Y


M2

S

25w

40w

N

0.4

100k

SE

0.05

500

15

M

P

Y


F5

S

25w

40w

Y

0.1

100k

SE

0.01

100

15

M

P

N


F4

S

25w

40w

N

0.2

47k

SE

0.05

50

0

M

P

Y


F3

S

15w

10w

Y

1

10k

SE

0.01

50

12.5

J

S

Y


F2

S

5w

10w

N

15

50k

SE

1

30

14

M

S

N


F2J

S

5w

10w

N

15

10k

SE

0.3

30

14

J

S

N


F1

S

10w

7w

N

80

100k

Both

0.1

30

15

M

BS

N


F1J

S

10w

7w

N

60

10k

Both

0.05

30

15

J

BS

N


Aleph J

S

25w

13w

Y

0.4

240k

Both

0.05

100

20

M

S

N


Notes:

Distortion figures are at 1 watt into 8 ohms at 1 Khz. See the specific product information for more detail.

Noise figures are unweighted from 20 Hz to 20 Khz.

For Damping Factor, divide 8 by output ohms, for example, 8 ohms / 0.4 ohms = 20

Bal/SE means XLR and/or RCA input connectors.

F1, F1J, F2, F2J, F3 are single gain stage amplifiers. The others have two stages.

Mosfet/Jfet refers to the output transistors. Two-stage amps with Mosfet outputs have Jfet input devices.

All amplifiers are available in 240 or 120 volts AC. Consumption ranges from 160 to 200 watts. All amplifiers operate at temperatures between 45 and 55 deg C.





Line Stage Products

As with the amplifiers, at one point I ordered up a bunch of metal to put line level electronics in. Here's what has occurred so far, some of these still in progress.


B1 - A stereo buffered passive volume control with two inputs. The buffer circuit is a simple Jfet follower operated with no feedback.


B2 - A stereo buffered bi-amp splitter with relative level adjustment for high and low power amplifiers. If you are bi-amping it is very likely that you need this.


B3 - A stereo gain stage with one pair of inputs, two level controls and a high gain / high voltage swing stage with no feedback. Suitable as a front end for power follower amplifiers and also for bridging and/or isolation.


B4 - A stereo active crossover with adjustable frequencies, slopes, and level. Active circuitry is provided by Jfets operated with no feedback.

B5 - A stereo active crossover with adjustable frequencies, slopes, and level. Like the B4 but filters and equalization for full-range drivers with woofers in open baffles.


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