the matrix amp

ETF.03

Steve Bench

The Matrix Amp

1

Talk Outline

This file gives an overview of the presentation to be given at the workshop. One of the MatrixAmps (7695) has been constructed for ETF2003. It is typical of the “matrix sound” (whateverthat means). However, it is slightly less polished than some other members of the family. This isdue in part to the use of power transformers (!) for input and output audio transformers, as wellas a desire to highlight the characteristics of the matrix amplifier. That is, it sounds like it is aMUCH more powerful amp than it is, it is inherently inexpensive, and can be very compact andlight. The 7695 amp is small (200cu inch), light (7 pounds) and cheap (about 100 USD), yet pro-duces some reasonably impressive sound. This talk discusses the matrix amp and some relatedtopics of interest to the audio community.

Prepared by Steve Bench [email protected]

2

Overview of the Matrix amp

• Background

• How does it work

• Refer to GEN_MAT1I (page 9). For illustrative example, assume the amplifiers are true voltagesources (i.e., 0 ohms) and the transformers have a 10:1 turns ratio (100:1 impedance ratio). Youcan look at this as a 1k impedance on each half of the primary translating to 10 ohms on eachhalf of the secondary for the tapped transformer and 1k to 10 ohms for the untapped transfor-mer. Now, feed a signal into the left channel only. GEN_MAT2. Since the amps are defined as vol-tage sources, that means that point C has 0 volts on it, half at point B, and the other half A-B.(Autoformer action, it doesn’t matter that effectively there is a parallel transformer from B toC). The vectors on the secondaries then show 0.5V from D to E and another in phase 0.5V fromE to ground. Since the left speaker is connected D to ground, 1 volt is produced. Note that since10V from the source translates to 1 volt at the load, the same 10:1 voltage ratio is produced bythe matrixing system. Note that the vectors subtract for the right speaker (the heads of thearrows face each other) so no sound is produced in the right speaker, which is what is desired.GEN_MAT3 (page 10) describes the system with the right channel driven.

• Limitations (historical)

• Crosstalk limited

• Since one side needs to be “inverted”, was deemed useable only with ceramic/crystal phonostages where the inversion was accomplished at the cartridge.

• One transformer has DC flowing in it. (parafeed was apparently never a consideration.)

• Speaker connections are “odd” in that one side + is ground. This would have confused a lot ofpeople in a “general purpose” amp.

• Effects of source resistance on crosstalk and performance were more difficult to envision, sofeedback was sometimes used as an attempt to “fix” this problem. In this topology, it madethings worse.

• SPICE etc tools not available.

• Modeling (SPICE)

• Basic model is shown in ETFMAT1.TXT. (Hint: if you rename this to ETFMAT1.CIR, it will open upin AIMSPICE directly and allow you to do an AC analysis.)

• SPICE clearly shows the limitations of this topology. See RES1 and RES2 (page 17).

• Overcoming the limitations

• Basically, one limitation to remove is the somewhat limited midband channel separation. Thiscan be done by adjusting the turns ratio of the second transformer, adding a small resistor inseries with the feed-in of the second transformer, and placing a capacitor across the first trans-

3

former to cancel the effects of leakage inductance. (ETFMAT2.TXT, RES3, RES4; both page 18). Apractical consideration that would be nice is to keep the transformers the same. But there is DCin one and not in the other. This is easily fixed by parafeeding the second transformer. We willdiscuss how much leeway you have in selecting these components later.

Characteristics of the Matrix amp

• Apparent power

• One of the characteristics that everyone who has built one of these amps or listened to it hasconsistently noted is that the matrix amp SEEMS to be a much more powerful amplifier than itmeasures. Why? Compare 50C5DIS (page 14) with D_1060_2 (page 16). In particular note thatfor a “traditional” amplifier with no global feedback, the difference between 1% and 3% distorti-on is about 2dB. (50C5DIS). With the matrix, this is extended to about 3dB. This means that dis-tortion is growing more slowly , and this translates to a perception of greater power. Also, com-pare RES3 top curve with RES4 top curve. As both channels are driven the bandwidth extends.Now compare D_1060_1 with D_1060_2. With both channels driven, the available power AT ANYDISTORTION LEVEL increases by about 2dB. These 3 effects combine to cause the matrix toappear more powerful than its rating.

• Note what happens when both channels are overdriven. So long as the signal is mostly com-mon, the channels go into a “distortionless” Class AB operation. (There is no signal in the“second” transformer – more on this later). This actually provides additional power and explainsthe 2dB measured difference in PO.

• SE sound

• Examination of the schematics show that each “channel” is a SE amplifier that is somehowmagically combined in the output transformer primary and separated in the output transformerssecondaries. The amps SOUND like SE amplifiers.

• Components surrounding the amp

• Note RES5.GIF. Here, I have purposely used insanely undersized parafeed components. Yet,compare RES4 with RES6. They’re the same! For low frequencies, where channel separation isunimportant, there is NO signal in the lower transformer. This has an interesting ramification ifyou think about it. We are always trying to minimize the number of components in the signalpath. Here’s a two channel amp that depends on only 1 transformer for its character. Note theschematic 7695MAT (page 11). The amp you’re listening to has a 1.5Hy parafeed choke! I did thatas an illustration of how insensitive the topology is to those components.

4

• Why pentodes?

I’ve built matrix amps with “all 4 permutations” of driver and output. Here’s the subjective“quality” of the resulting sound:

Discussion…

Matrix amp discussion

• Inherent shortcomings

• Does not like speakers with high order crossovers. Compare RES7 with RES8. This shows thedetailed response of one of the channels with both driven. The shown channel is loaded resisti-vely, but the NON-SHOWN channel is loaded with a complex load (LCLC along with R).

• Performance appears to be sensitive to power supply quality. (moreso than conventional SE)

• Inversion in one channel requires either input transformer or an “odd” stage.

• What are additional uses for this topology

• This topology is inherently smaller, and lighter than “conventional” amplifiers. For situationswhere several amplifiers are needed (e.g., home theatre) this would seem ideal.

• Small side installations.

• Why wasn’t the Matrix originally successful?

• Since there were no “EDA”, getting good performance was not necessarily obvious.

• Topology regarded as a “cheap fix” when more-complex-is-better thought prevailed.

• See also limitations listed above.

5

Driver Output Resulting Sound

Triode Triode fair

Pentode Triode much better

Triode Pentode worst

Pentode Pentode best

Overview and review of the constructed Matrix amps

• YL1060

• First constructed matrix. Is unusual in a couple of respects:

• Has “blend / anti-blend” control

• 2 tubes for a stereo amp. Both dual tetrodes.

• matrix

• Also the distortion curves show one channel and both channels driven.

• KT88

• Follow on from above. More conventional. This has been constructed by several people. Likesto be played loud!

• Amp and PS schematics shown.

• 6MB8 input stage (triode-pentode… one of the triodes is used as the “inverter” the other oneis in the power supply as a shunt regulator).

• Some people have reported slight constriction at low levels. See 813 amp.

• 813

• Big brute version; 60 or more watts per channel.

• All power supplies regulated. Supplies somewhat “unusual”.

• Originally constructed with same front end (6MB8) as KT88 version, later changed to 6GX7(slight pin change but NO circuit value changes).

• It is very difficult to overdrive this amp.

• With 6GX7 front end, there is no low level constriction at all.

• Complex, but good. Note that the distortion at 1 watt is about 0.03%.

• 7695

• Very small, very light, inexpensive.

6

Interrelated Topics

• Feedback

• Characteristics of feedback

• When is it “acceptable”

• Local vs global

• Feedback in pentode stages vs feedback in triode stages

• Is an amps sound determined by the driver or the PA stage device?

• Compare D_813MT2 and D_813MT3 (page 15).

• Discussion

• To probe further

• Discussion

7

A A

B B

C C

D D

E E

44

33

22

11

44

44

55

33

7695

7695

6GU

56G

U5

110V

120V

152V

150V

148V

12V

Yel

Blk

Vio R

ed

Grn R

edB

rn

Blu

Not

e re

vers

e ho

okup

left

/rig

htLe

vel

12V

12.9

V

12.9

V

148V

138V

138V

45V

45V

Yel

Yel

Blk

Blk

Vio

VioR

ed

Red

Grn

Grn

Red

Red

Brn

Brn

Blu

Blu

(c)

Cop

yrig

ht,

2003

Ste

ve B

ench

. A

ll R

ight

s R

eser

ved.

Spk

r Ja

ck

Spkr

Jac

k

138V

128V

0.4V

0.4V

Not

es:

Sen

siti

vity

: 26

5mV

at

J1,2

= 1

wat

t.Z

out

= 4

ohm

s. I

nten

ded

for

8 oh

m s

peak

ers.

Am

veco

/To

lem

a to

roid

s av

aila

ble

from

Dig

i-K

eyL1

is

Ham

mon

d.C

3 is

non

pol

ariz

ed,

not

elec

trol

ytic

Re

spo

nse

: -.

7d

B a

t 20

Hz,

-.6

dB a

t 20

kHz.

-3d

B a

t 40

kHz.

Dis

tort

ion:

Abo

ut 1

% a

t 2.

5WM

ax o

utpu

t =

3.5W

per

cha

nnel

.S

elec

t m

atch

ed 7

695

and

mat

ched

6G

U5

7695

Mat

rix

A

7695

Mat

rix

Am

plifi

er

A

11

Mon

day,

Aug

ust

04,

2003

Titl

e

Siz

eD

ocum

ent

Num

ber

Rev

Dat

e:S

heet

of

Left

+

Left

-

Rig

ht+

Rig

ht-

o oooT5

Am

veco

115

+11

5:9+

9 50

W1

5

26

3 4

7 8

J3 115V

S1

Pow

er F1

1.5A

SB

D1

FR

307

D2

FR

307

D3

FR

307

D4

FR

307

D5

FR

307

D6

FR

307

t

RT

1C

L40

R26

68 5

W+

C11

1000

u 16

0V

+

C10

1000

u 16

0V

+C

6

1000u 160V

+C

7

1000u 160V D7

12V

5W

+C

1210

00u

16V

R20

10 3

WR

2110

3W

R25

100k

2W

R24

100k 2W

+

C5

2200

u 25

V

+

C4

2200

u 25

V

R19

5.6

5WR

2233

0 1/

2WR

231.

6k 1

/2W

+C

8

33u 160V

+C

9

33u 160V

o oooT1

Am

veco

115

+115

:22+

22 3

.2W

15

26

3 4

7 8

o oooT3

Am

veco

115

+115

:22+

22 3

.2W

15

26

3 4

7 8

J1Left

In

J2 Rig

ht I

n

R2

50k

R13

50k

2,

V2

6GU

55

6

73

4

1

2,

V3

6GU

5

5

6

73

4

1

R5

1k

R15

1kR9

75

R10

75

R6

20 R14

20

R3

30k

R16

30k

V1

7695

9

16

74

5

V4

7695

9

16

74

5

C1 1u

200

V

C2

1u 2

00V

R7

330k

R12

330k

R4

1k

R17

1k

R8

10 3

WR

1110

3W

R1

100k

R18

100k

o oooT

2A

mve

co 1

15+

115:

7+7

50W

15

26

3 4

7 8

o ooo T

4

Am

veco

115

+11

5:7+

7 50

W

15

26

3 4

7 8

C3

30u 100V

L1 1.5H 200mA

17

Top: Res1.gif Bottom: Res2.gif

18

Top: Res3.gif Bottom: Res4.gif

19

Top: Res 5.gif Bottom: Res6.gif

20

Top: Res 7.gif Bottom: Res8.gif

Measurements of the ETF.03-Matrix Amp (by Christian Rintelen)

Both channels driven into clipping (16 ohms) – noteassymetrical clipping

21

Both channels driven (reference tone: square wave equivalent to 1 kHz with 5% THD into 16 ohms)

Ω 20 Hz Ω 50 kHz≈ 100 Hz ≈ 1 kHz

2222

Phase behaviour (sine wave; reference: 1 kHz, 5% THD into 16 ohms)

Ω 20 kHz Ω 30 kHz≈ 40 kHz ≈ 50 kHz

Ω 10 kHz Hz Ω 20 kHz

Christian Rintelen’s measurements of Steve’s ETF.03-Matrix amp:

1. Output:Both channels driven into 16 ohm load; 1 kHz into visible clipping:left channel 5,2 V RMS = 1,7 W, right channel 5,4 V RMS = 1,8 W

2. Output vs. distortion(bear in mind please that the el-cheapo ETF.03-Matrix amp is uses toroid power transformers asinput and output transformers!!) both channels driven into 16 ohm load, all power levels measu-red at 5% THD200 Hz: L = 2,0 W, R = 1,9 W1 kHz: L = 2,0 W, R = 1,9 W10 kHz: L = 1,8 W, R = 1,8 W20 kHz: L = 0,4 W, R 0 0,6 W

3. Distortion vs. frequency(input: sine wave referenced to 1 kHz into 16 watts (both channels driven) and 5% THD). Outputreferenced in dB to 1 kHz input signal = +/- 0dB

left channel right channelTHD output THD output

20 Hz 56% (!!) - 1,35 dB 55% - 1,41 dB50 Hz 5,6% + 0,2 dB 6,6% + 0,2 dB100 Hz 4,53% 0 dB 5,6% 0 dB1 kHz 5% 0 dB 5% 0 dB10 kHz 9,1% + 0,4 dB 8,9% + 0,4 dB20 kHz 22% + 0,6 dB 21% + 0,6 dBS

23

Steve Bench’s measurements of his 813 Matrix Amp

(8 ohm load, both channels driven)

Power = 1 watt20Hz 0.05%100Hz 0.04%1kHz 0.035%5kHz 0.045%10kHz 0.08%20kHz 0.09%



Power = 50 watt20Hz 6% (on verge of saturating the iron)100Hz 2.5%1kHz 3.0%5kHz 3.5%10kHz 4.0%20kHz 4.1%

Power = 60 watt20Hz 10% approximately ... saturation evident100Hz 4%1kHz 4.5%5kHz 4.5%10kHz 5%20kHz 5.2%

24

252525

Rows 1 and 2 show the 60W 813 Matrix amp (measure-ments next page)The picture to the left shows the KT 88 Matrix amp withthe 813 for comparison…

Some pictures of other Matrix Amps

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2

1 1(c ) Copy r igh t , 2003 S teve Bench. Al l Rights Reserved.

Left Spkr

Right Spkr

Interconnect

+750VDC

Set idle currentto 100mA ( 1 voltacross 10 ohm.)

+787V

+772V

+772V

-60VDC_aboutBias voltage is

200V

200V

150V

Volume

1.3V

1.3V

Note : Po la r i t y o f R igh t Input connect ion to transformeris inverted with respect to left input.

1V

1V

11V

11V

1V

1V

7V

7V

On Front Panel

C

813 Matr ix Ampli f ier

A

1 1Monday, June 02, 2003

813 Matr ix Amp

Tit le

Size Document Number Rev

Date: Sheet of

Left-8

Left-0

Right-0

Right-MonGround

Right-8

Left-Mon

+750VDC

+10V-1+10V-1Rtn

+10V-2Rtn+10V-2

Bias2

Bias1

+200V

+800VDC

Ground

+150V

813V1cap

34

1 7

5

o

o

o

o

o

o

T2Lundahl 1660

9 21

8

18

13

16

10

72

53

4

o

o

o

o

o

o

T6Lundahl 1660

9 21

8

18

13

16

10

72

53

4

R7 10 1

% w

w

R2100

R10100

T1 Lundahl 1620PP4

25

73

16

81112

13

14

1516

17

18

19

2021

22

23

2425

26

C3

20u 100V NP

813V3

cap

34

1 7

5

C1

.1u 1kV

R8 10 1

% w

w

R4N.U.

R13N.U.

R16 10 3W

R18 10 3W

R15 150k 5W

R1 150k 5W

V26MB8_P

6

7

8 4 5

9

V46MB8_P

6

7

8 4 5

9

R17

100

R3 100

L1Lundahl 1673-10H

1

36

7

T4 Lundahl 1620PP4

25

73

16

81112

13

14

1516

17

18

19

2021

22

23

2425

26

C4 .1u 1kV

C7 10nF 100V

C2.1u 1kV

C6 10nF 100V

C5.1u 1kV

R9100 1%

R11100 1%

T3 tr_Lundahl15401

2

3

4

E

5

6

7

8

T5tr_Lundahl1540

1

2

3

4

E

5

6

7

8

R650k

R1250k

R51k

R141k

J1Left Input

J2 Right Input tR T 2 KC024L (CL101)

tR T 1 KC024L (CL101)

I monitorI Monitor

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2

1 1(c ) Copy r igh t 2003 , S teve Bench. Al l Rights Reserved.

+750V+800V

+210V+200V+150V

150VPS LED200VPS LED

ScreenSupply LEDPlateSupply LED

HV LED

HV and LVPS Chassis

Neg, Bias and FilamentChassis

AC Line

AC Line

Power Swi tch

1 +800V2 N.U.3 Ground4 +200V5 Bias26 Mon Right7 +10V-18 +10V-1Rtn

9 +750V

12 +150V

10 N.U.11 Ground

13 Bias114 Mon Left15 +10V-216 +10V-2Rtn

L Spkr +L Spkr -

R-Spkr +R Spkr -

AmpChassis

Input Transformers

and Volume Contro l

on Front Panel

Indicators

on Front Panel

+210VGroundUM81 Fi l+UM81 Fi l -Mon LeftMon Right

-100VGround

1 -100V2 Ground3 Bias14 Bias 25 Ground6 +10V-1

7 +10V-1Rtn8 +10V-2

9 +10V-2Rtn10 -100VSupplyLED

11 UM81 Fi l+12 UM81 Fi l -

I_Monitor LI_Monitor R

1V = 100mA

LEDs on front panel.

813 Matr ix Amp A

Module Interconnect ions etc.

A

1 1Friday, May 16, 2003

Tit le


Date: Sheet of

Left Input

Right Input

Green

Green

Green

Green

Yel low

Yellow

Yellow

Blue

4.7k

2k 2k

5 .1V 250mW

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2

1 1(c ) Copy r i gh t 2003 S teve Bench. Al l Rights Reserved.

+750V

+149V

+149V

+212V

+212V

+600V

+600V

+700V

+700V

+800V+950V

Note: B+ Adj. range:about 750V to 840V

Note: LVPS on same chassisbut shown on i ts own schematic.

RT1-RT4 are Inrush Current L imi tersKC009 (CL90) parts.

Notes:HV PS and LV PS bui l t on same chassis.Nega t i ve (b i as ) and Amp Fi lament supply on separate chassisAmpli f ier bui l t on separate chassisL E D s a n d Level "Magic Eyes" On front panel

T h i s symbol indicates connect ion wi th in same chassisT h i s s y m b o l i n d i cates interconnect to di f ferent chassisT h i s symbol indicates Reference Voltage used in

other p laces on the same schemat ic page

B+Adj.

813 Matr ix Amp B

HV Regulators

A

1 1Friday, May 23, 2003

Tit le


Date: Sheet of

To Plate Supply LED

+800V Output

To HV LED

-100V Reg Input

+750V Output

To Screen Supply LED

+150V

+150V

+150V

+210V

+210V

+210V

117V

400-

0-40

06.3V

T1 Hammond 278CX

D1 UF1007 D2 UF1007

D8 UF1007D7 UF1007

D3 UF1007 D4 UF1007

D5 UF1007 D6 UF1007

+C2

1500

u 25

0VR6

82k

2W

+C4

1500

u 25

0VR13

82k

2W

+C6

1500

u 25

0VR17

82k

2W

+C7

1500

u 25

0VR18

82k

2W

+C8

1500

u 25

0VR20

82k

2W

D10

5.1V

250

mW

V1 6080

1

23

4

567

8

R2 68 5W

R5 68 5W

R1 1k

R7 1k

R8470k

V2 12AX71

2

3

4 5

6

7

8

9

R3

300k

1%

R9

300k

1%

R1550k 2W ww

R21

249k

1%

+ C147u 450V

R4

180k

3W

R10

180k

3W

D9

5.1V

250

mW

+ C547u 450V

C3

22n

1kV

R12 220 5W

R16 1k

R19 1k

R11 220 5W

R14 470k

V4 12AX71

2

3

4 5

6

7

8

9

+ C1247u 450V

R22

180k

3W

R25

180k

3W

D11

5.1V

250

mW

+ C1447u 450V

117V

125-0-125

6.3

T2 Hammond 261E6

F18A

J2Jack for -Regulator supply

J1Power (Line cord)

S1Power

tR T 2

tR T 1

tR T 3

tR T 4

LP1

120v 75w

V360801

23

4

567

8

C9

.1u 250V

R28 100k

R27 100k

C11

.1u 250V

R23300k 1%

R24300k 1% C13

22n 1kV

R26249k 1%

C10.1u 250V

250VAC to .. . .

. . .LVPS Rect

+210V Ref (LVPS)

+150V Ref (LVPS)

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2


Input t ransformers and loudness on front panel

Matr ix Amp A

Alternative Input - as built.

A

1 1Friday, May 16, 2003

Tit le


Date: Sheet of

To 6MB8 gr id resistor (R5)

To 6MB8 gr id resistor (R14)

50k 13ktap

tr_Lundahl15401

2

3

4

E

5

6

7

8

20k

20k

20k

2k470pF SM

Left Input

2k

1u 200V

2k

tr_Lundahl15401

2

3

4

E

5

6

7

8

470pF SM 50k 13ktap

2k20k

Right Input

20k

1u 200V

20k

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2


250V

Note tha t the Zener str ing only conducts duringlow or no loads (startup) and with normal load,i t is not conducting.

Notes:HV PS and LV PS bui l t on same chassis.Nega t i ve (b i as ) and Amp Fi lament supply on separate chassisAmpli f ier bui l t on separate chassisL E D s a n d Level "Magic Eyes" On front panel

T h i s symbol indicates connect ion wi th in same chassisT h i s s y m b o l i n d i cates interconnect to di f ferent chassisT h i s symbol indicates Reference Voltage used in

other p laces on the same schemat ic page

250V

250V

+210V

+200V

+150V

-97V

-97V

-100V

+211V

+201V

+151V

+0.6V

+0.6V

+0.6V

Note: Al l three 2n2583 are TO-66 package and shouldbe hea t sinked using a T0-66 Heat sink of 10 degreeper watt or better heat sink.

T h e 210V supply dr ives UM81 indicators and isinternal reference used in HVPS.

T h e 2 0 0 V s u p p l y provides plate supply for 6MB8.

T h e 1 5 0 V s u p p ly provides screen grid voltage for6MB8, and internal reference for HVPS.

813 Matr ix Amp A

LV Regulators

A

1 1Saturday, May 24, 2003

Tit le


Date: Sheet of

-100V (also used on HVPS)

Gnd (a lso on HVPS)

+210V

+200V

+150V

150VPS LED

200VPS LED

-100V Ref

-100V Ref

+210V

+210V

-100V Ref

-100V Ref

D1 UF1007

D5 UF1007

D2 UF1007

D3 UF1007

R1 620 10W

+C233u 350V

L1 1Hy 75mA

+C347u 350V

D4 28V 5W

D8 28V 5W

D10 28V 5W

D16 28V 5W

D13 28V 5W

D7 28V 5W

D9 28V 5W

D11 28V 5W

D14 28V 5W

D17 28V 5W

R15300k 1 /2W

C70.1u 250V

Q 1 2N3583

Q 2 2N5656

R647k 1 /2W

R3 13k

+C4

22u 250V

R4 13kR2 10 +C1

22u 250V

R5100k 1%

R747.5k 1%

D6 UF1007

Q 3 2N3583

Q 4 2N5656

R1247k 1 /2W

R9 20k

+C6

22u 250V

R10 20kR8 10 +C5

22u 250V

R11100k 1%

R1347.5k 1%

D12 UF1007

D18 UF1007

R14 10

R2015k

R1915k

Q 6 2N5656

R1875k 1%

+C822u 250VR16 15k

+ C9

22u 250V

R2147.5k 1%

Q 5 2N3583

R17100k 1%

D15

5 .1V 250mW

D19

5 .1V 250mW

250VAC f rom HVPS

250VAC from HVPS

+210V

+150V

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2

1 1

Sens

itivit

ySe

nsitiv

ity

S e t sens i t i vity for "ful l scale" = 20WNote : Max sens i t i v i t y i s ful l scale = 8 watts.

( c ) Copy r igh t 2003 , S teve Bench. Al l Rights Reserved.

Matr ix Amp A

Signal Indicators

A

1 1Friday, May 16, 2003

Tit le


Date: Sheet of

Left Mon

Right Mon

+210V

UM81 Fi l+UM81 Fi l -

Ground

V1UM81

9

1

2 4 5

7R31MegC2

0.1u 50V

R21.8k

C11u 200v

D21N5818

D11N5818

R1 510k

V2UM81

9

1

2 4 5

7R61MegC4

0.1u 50V

R51.8k

C31u 200v

D41N5818

D31N5818

R4 510k

A

A

B

B

C

C

D

D

E

E

4 4

3 3

2 2

1 1

AstecLPS6312V 6ASMPS

L

N

E

123

456

+

-

Astec3

4

N

E56

+

12V 6A

-

LPS63

12

SMPS

L

(c ) Copy r igh t 2003 , S teve Bench. Al l Rights Reserved.

+

N e g a t ive and Fi lament Supply Connector

-170V

About 16.5V

SD

G

leads short,Keep these

-85V -85V

-84.4V

-100V

-100V-104V

Optical ly Coupled

Note: IRF9630 is a TO-220 partmounted on a heat sink of10 degree per watt or better.

Bias1Adj.

Bias2Adj.

Bias vol tage adjustment rangeis about -35 to -80V.

A s tec suppl ies are adjusted for about -11.5Vand this al lows about 1.5V drop in the wir inga nd connectors to the 813 sockets.

Note that al l the f i lament suppl ies areunreferenced at this end.

-3.4V

-6.8V

1 2 V 100mA fan moter to cool Astec suppl iesRuns on about 9V to keep noise down.

N o te Schottky Rectif iers

813 Matr ix Amp A

Negative Reg and Fi l Supply

A

1 1Sunday, May 25, 2003

Tit le


Date: Sheet of

12 UM81 Fi l -

10 -100VSupply LED9 +10V-2Rtn8 +10V-27 +10V-1Rtn6 +10V-15 Ground4 Bias2

1 -100V Reg output2 Ground3 Bias1

11 UM81 Fi l+

117V

125-0-125

6.3

T1 Hammond 261E6

F11.5A SB

J1Power

D4 3A 30V

D5 3A 30V

+C5

15000u 15V

+C6

15000u 15V

M1 12VDC Fan

R16 22

C7.47u 25V

D1UF1007

D3UF1007

R3 100 1W

+ C233u 250V

+ C3

1800u 200V

R5220k 1 /2W

Q 1 IRF9630R4 10

D2 12V 250mW

R72k

R615k

R815k

+

C4 22u 200V

R1 68k R2 12k

Q 2 MPSU60Q 3

MPSU60

R1122k

R97.5k 1%V1 5783

2 31

R1040.2k 1%

D6

Whi te LEDD75 .1V 250mW

+ C110u 160V

R1215k

R17

50k

WW

R2136k

C8

.47u

100

V

Q 4

MPS

U10

R18100

R1336k

R1415k

R19

50k

WW

R2236k

C9

.47u

100

V

Q 5

MPS

U10

R20100

R1536k

the matrix amp

Documents