Mullard - Preservation Sound

Mullard
a -\
,
a
a
aI
I
,,W
,'W
.%
,W
,W
,W
am
,m w
t_____
-----7
,
ta-r'
,
,
,
,
,
,
,
t
t
,
nqde
music
for
A nign gain pentode of special design, the EF86 is particularly suitable for
preamplifier and input stages, in which hum, noise and microphony must be kept to a
minimum. The low frequency noise generated by the valve is equivalent to a voltage ot
2pV on the control grid for a bandwidth from 25 to 10,000 c/s. The electrode structure
has been made particularly rigid to keep the microphony of the valve to a very low
level. There are no appreciable internal resonances below 1.000 c/s, the vibration at
higher frequencies being effectively damped out by the chassis and the valveholder.
EF86
Hum is kept to a minimum by winding the heater as a bifilar twisted pair of
wires, with the magnetic field of the one wire opposed to that of the other, Effective
internal screening reductis the internal valve capacitances through.which hum can be
transferred to the outaut. The screening also shields the electrode structure from the
alternating fields set up by transformers, etc., which otherwise would induce a.c. mains
frequency currents in them.
LIMITI NG VAL
HEATER
Suitable_for series
or
Vr
l,
6.3
0.2
300
200
0.2
V
A
Ps2 max.
6.0
3.0
t0
t50
t00
20
lk max.
CHARACTERISTICS
Rst-k max. (pa> 0,2 W)
Rsr-k max. (p. <0.2 w)
Vh-k max. (cathode positive)
Vh-k max. (cathode netativ€)
250
0
t40
ta
U ES
parallel operation,
3
lc2
MO
2.5
38
vzl-22
v
w
mA
t4 c)
Ma
v
v
ka
as a phase inverter immediat€ly
preceding the output stage, Rh-k max. may be
t.8
8m
v
r20k
o.
Exact plug-in replacements for the most troublesome tubes in audio and
electronic equipment. lvlullard special design and construction, including special mica
supports and jnternal structure make these tubes superior particularly in critical high
gain circuits where the lowest levels of hum, noise and microphonics are a necessity.
ECC83
or phase spliiters
can conveniently be bujlt around high-mu
R-C coupled ampJjfiers
double tnooes wrth sepdrate cathodes. ln partrcular,the ECC83/I2AX7, with an arpl;f'rcation factor oi 100, has adequate gain in the
carhode
type phase splitte. Lsed in
the
ECC82
ECCSI
12Af?
"oJpled
lVJlla'd
510
ampliJier circuits.
and )20
h
gh
fidelity
100
3.0
t"
-1.0
8.
3.75
62
16.5
F
21
for
series
or
Porollel
12.6
0.15
6.3
0.3
V
A
ECC83
100
0.5
-1
1.25
100
80
LIMITING VALUES
max.
max.
p' max.
lk max.
max.
-Ve
*Rs-k max.
Vh_k max.
iRh-l max.
V&rrr)
Va
n n ,.o,
*./oooo) e
o'\% oo,/ *
*With
trid
lk max.
vg
0s:
+0.3FA
Vr,-* max.
Rb-r
250
1.2
-2
v
mA
V
1.6 mAlV
100
62.5
k
o
(each section)
550
300
1.0
8.0
50
2.2
180
20
V
V
W
mA
V
MO
V
kO
current biasint Rg-l max.:22 MO.
max'
ko
ko
(each section)
R!-x max. (self-bias)
CHARACTERISTIcS (each scction)
vr
l"
vs
8h
p
rtr
200 250
't1.5 10
-2.0
-1.0
6.7 5.5
70 60
10.s 11
14 75
parallel operation,
Series
Vr
L,
(each section)
at 50 Mc/s
LlMlTl NG VALUES
H EATE R
Suitable
.)'---(.,
v.
*Measured
124U7
".
ECC8l
CHARACTERISTICS
Eccg2
550
300
2.5
'15
50v
-1.3
1.0
150
20
V
v
W
mA
V
MO
V
ko
CHARACTERISTICS (eech section)
v"
100 2s0
l"
vs
tm
t!
rr
12
0
3.1
19
6.2
LIMITING VALUES
p&
lk
max.
max.
V!
k
max.
v
mA
V
2.2 mA/V
17
7.7
kO
(each section)
bia5)
bias)
Rg-k max. (cathodc
Rg k max. (fixed
10-5
-8,5
550
300
2.7s
20
1
250
180
MO
ko
ko
used as a phase inverter immediately preceding *When used as a phase invefter immediately preceding
the output stage, Rb_* max. may be 120k O.
the output stage, Rh-k max. may bc 120 k O.
twhen
Et84
When operated in a single-ended output stage, the EL84 can deliver an output
5.7W, and two EL84's in pentode push-pull yield an output of up to 20W.
As these figures suggest, this valve makes available the higher peak powers and low
distortion required for present day medium power amplifiers used in High Fidelity equitr
of up to
ment, tape recorders, phonographs, movie projectors, AN,4/Fl\4 radios.
The EL84 requires unbelievably low drive voltage thereby eliminating the
necessiiy of preceding high gain stages. The EL84 has a very high mutual conductance
ot 11,300 u-mhos and a plate dissipaiion of 12W.
LIM ITI NG VAL U
H EATE R
ES
300
300
2.0
6.3
lr
0,76
ps2 max. (zero siSnal)
ps2 max. (lnex. signal)
lk max.
CHARACTERISTICS
250
t"
lc2
55
t.0
300
100
Rst-k max. (cathode bias)
Rgt-k max. (fixed bias)
250
48
5.5
*lf the heater, anode,
-7.3
lLl
th
ko
38
v
v
w
mA
Mo
ko
v
and screen-trid voltages are
obtained from an accumulator by means of a
vibrator, Va max. 250 V, Vs2 max.:250 V,
l9
EL34
Amplifiers which provide nominal outputs of from 30 to 50 watts to handle
the loudest music, or even higher powers for publ;c
output stage equipped with two EL34's in push-pull.
An interesting
of
address equipment, include an
the push-pull output stage (Fig.
1)
The maximum plate dissipation is 25W with a high mutual conductance
oJ
method
connecting
has been used in a recently published Mu llard-designed 520 amplifier, The screen grids
of the EL34's are connected to taps on the primary of the output transformer, so that
the operating conditions lie somewhere between those of a triode (,,tap,, connected to
anode) and those of a pentode (screen grid connected to primary centre-tap). Thus the
low distortion of a triode js combined with the high sensitivity of a pentode. Ihe valves
are said to be operated with distributed load (ultralinear). The linear characteristics of
the EL34 coupled with the extremely low driving voltage make the EL34 truly the
world's finest output tube.
For public address equipment, line voltages of up to 800V can be used, and
two EL34's in pentode push-pull with fixed bias glve an output of up to IOOW.
11,000 u-mhos
LI MITI
HEATER
lh
th
r.
t.5
pa max. (max. signal speech
music)
P!l-!2
250
Pg2 max
250
0
'lk max.
Rst-k max. (cathode bias)
Rsr-k max. (fixed bias)
100
14.9
-13.5
ll
15
II
U ES
Va
CHARACTERISTICS
v"
Ve2
Vei
L
lz2
Ver
NG VAL
max.
Pa max.
6.3
and
800
25
27.5
42s
8.0
r50
700
500
t00
ko
ko
ko
PRELIA/lrNARY DAIA
HEATER
EZ80 EZ8I
EZg1
6.3
0.6
l6
LIMITI NG VAL
U ES
max.
P.l.V. max.
ja(pk) max.
lour max.
C max.
*vh-k(pk) max.
* Heater ne8ative,
v: {. m.s.)
EZ80
6CA4
6V4
V
A
LIMITING VALUES
max.
2x350
l"ut max,
90
C max.
50
(per
ia{pl) max.
anode) 270
vh-k(pr) max.
500
V1115s.1
TYPICAL OPERATI
V. (r.h.'.) 2x
c50
+Rlim min.
lo.r
Vour
pF
250
2x300 2x350
l2S
50
300
90
265
t.0
450
l5O
50
t0
l",t
c50
tRtin min.
V."t
pF
o
't
360
t50
150
24s
pF
500
TYPICAL OPERATI O N
Va(r.m.s.) 2x250 2x300
ON
50
2t5
90
3t0
350
t50
s0
200
a%
2x350
t50
pF
50
240
347
Per anode.
These three valves are low-impedance, indirectly heated, full"
wave rectifiers that oifer many benefits in elecironic circuitryi
1. Better voltage regulation due
imp-dd,,L :,
to
lowered power supply
2. Higher output voltage and cooler operation due to
lower
voltage drop;
3. Protection of costly filter condensers and power output
valves due to delayed warm-up and reduced ripple.
GZ34,due to its compactness and unique characieristics
is an excellent replacement for most high power rectifiers such as the
5U4G, 5U4GA, 5V4G, etc., at the same time offering the advantages as
Ihe
outlined above.
Gt34
The EZ81 is a miniature tube able to deliver 150 lVlA and
able to power most medium power amplifiers and pre-amplifiers.
The EZ80 and EZ81 are mounted on noval bases; the GZ34
on octal base.
PRE
L rAlll,
NAR
H EATER
LI
T.I
Y DArA
ITI NG VAL
U ES
550
1.5
750
250
60
5.0
Ir
t.9
i.(pk) max.
C max,
TYPICAL OPERATI O N
(r.m.s,) 2x300 2x450
V"
250
lout
c606060
50
tRrid min.
vou,
300
i Per anode.
250
125
450
2x550
t60
sF
l7S
6t0
a
V
kv
mA
mA
pF
TYPIGAL OPERATII{G GOI{DITIOI{S
E
F
86
:::::'lT:;T,:'It?i;,t:
E
L
PENTODE CONNECTION
R.
(ko)
l0o
l0o
100
100
r00
r00
220
220
220
220
720
220
(v)
,l0o
350
3@
250
200
t50
100
350
300
250
200
t50
lr"
(fra)
3.3
2.a5
2.15
2.05
t.65
t.o
t.55
l,,t
t.l
0.9
0.75
0.55
'Gid
Rs,
(r.1o)
0.39
0.39
0,39
0.39
0.39
0.47
r.0
t.0
r.0
t.o
t.O
t.O
R.
(!r
Rb
h
(ko)
220
no
220
220
220
D-r
l%)
5.0
s.o
5.0
5.0
5.0
s.O
5.0
5,0
5.0
5,0
5.0
s.0
!o:: tr to k)
Vout Vout. Dor"
-v;
vr.m.,. t%
12
71
3.8
3t.5 62
3.7
3t
5t
3.7
30.5 t9
3.5
30.5 28
l.t
(-^)
(ko)
t.05 3.9
0.9
3.r
0.8
3.r
0.65 3.9
0.5
r.9
'Ourput vok.t. .nd diitortion .t tra ol potitiv.
volt.tE
{v)
a00
350
300
250
2oo
th€ di3tortion ir
+Grid re.irtor ol tollowins
4 :;Ti,'i1i".,":^i ll,'f
pim.rY turn! (j.. trr,
Rr,.
130
330
330
45
62.5
2\ 65
2x 5.0
330
3lO
a
52
lo
6a0
Witi ..p..rt. ..r..n-trid
20
0,8
37
t,l
rlDply
..d lix.d bi!.
%
Th..r op.htinr .onditionr .pply with .r.bilbed li.. vohase. .nd .ltow for .
25V d.op in .h. prim.rr windins oI rhe ollDur rr.ndormer r! mrximuh .itn.l.
th.r. i..n &ldhionrl drop of 25V ir rhe line vohalet rr d.rihuh ti!..|
P.r:90W. Th. oDtimum .node{o-.node lo.d und.. ihere.ondirio.i h lll A.
Vb6)
&O
v
vh(rr)
4)0
v
750
O
'Rrz
It
0
2r25
sri.l <u.r€nr. At lower output
lpproriFat€lr oroport onrr to rh. vok.se.
velv€.
2x5.0
170
680
680
680
1t70
2\7.5
6€0
680
ko
x 61.5
470
17
6q)
681)
2
2r5.1
580
680
580
I
125
2x
!30
(ka)
,110
I
l3o
i
L"-
r,
{ko)
Rr
.?'"
Di.rribut.d lo.d-conlitionr with .(...n.trid c.ppin! .t {io{. of
..5i..or ol lollowin! v.lv..
TRIODE CONNECTION
vb
Rr Voq vod
(ko) \4; vrn.,
r.0 t2a 87
r.0 t20 75
t.0
6 6t
1.0
2 50
t.0 t06 10
t.5
95 22
2.2 20? 73
2.2 196 63
7.2 t88 5,1
a-a t80 ,t5
7.a t70 36
2.7 rso 21.s
3
\91
7
ls2
2r
(m.x. tir.)
7x
1.0
19
,3)
KQ
ECC 83
vb
(v)
&
350
300
754
200
{00
350
300
250
200
,loo
!50
300
250
200
R.
I
(ko)
17
17
a7
17
47
t00
ll)O
r00
100
t00
220
220
220
220
220
{m^)
2.45
l.9A
t.55
t.t8
0.
t.72
r.4
r.ll
0.86
0.65
r.o2
0.85
0.63
0.,l€
0.36
.Ou!pu! vok.t. .nd di3to.tion
*Sc...n-srid
A PHASE
Yt
(v)
250
250
350
350
Vout Vo,r' Dro."
Rrrr
-Vh
(v..-.,.) \"b
(ro)
{n)
680 4
17
1.6
tso
,(.,t
820 +.5
33
tso
t@0 10
26
5.0
t50
t200 37.s 23
7.0
t5o
1500 3a
l8
8.5
t50
820 6t
38
t.7
330
t000 61
36
2.2
330
1200 57
30
2.7
330
rso
5,t.5 26
it.9
t30
,{.8
1800 50
20
330
r2oo 75.5 3A
Lt
680
1500 75.5 37
|.6
680
2200 7a
36
2.6
680
2700 66.5 28
3.4
680
33@ 56
21
1.6
680
r!.t.rt ol pBiriye trid c!r.it. At lower ourput
propo.rion.l ro
th. voh.!..
ltor
t.oa
t.o8
1.7
1.7
Rr
a)
t200
t200
820
820
(
I
Vb lV. (.pprcx.) lr+ l.'
Rr,
(v) (v) {ma) (k9)
2so 65
t.0
6a
250 65
t.0
68
350
t.2
82
350 to
90
t.2
82
clRcutT
Vourl
Vout
-T;;
58
58
62
61
Dot*
V"r1
Vour
Dtof
zo
7
1s
to
E
2s
17
27
0.6
(ra) (v..-.,.) -izi
100
t00
t50
t50
(%)
5.5
Lt
3.5
0.7
(".)
t.8
t.8
0.5
.t.t .t ol p$itiv. rrid .urr.nt- At low.r output
th. di.tonion i! .pp.oxinr!.lr prctofrion.l to !h. roh.!..
tv hould b. .dius.d .o rhrt l:1 lr' . ln^ .r Vb 250 V rnd 1.2 hA .t v.
vok.te.nd di.to.tion
'Oulput
yolot.r
350 V.
I
<ommon
to both
%
valye5.
4 3'"Ti'JIl,: : i ",'l::)inii.,,,. *
tr
vi"('.-.'.1 (l.a=50 mw)
(06r:
1091,)
D,
(v....,.)
35
7
,tS
9
R"
EL
virk.h.,.)
Dl
INVERTER
CIRCUIT A
(m^)
r..i.to.
W
(with .arhode biat
TYPICAL OPERATING CONDITIONS
AS
100
5.0
Rr
ih. di.todon i3 .pp.orin.t.ly
tcrid rsi*or ol followin! v.lve.
voh.t.1
Pour
Dtot
OPERATING CONDITIONS AS
R.C. COUPLED A.F. AMPLIFIER
250
250
5.2
250
250
l]5
t35
'1.5
-7.X
-7.3
a8
5.5
0.3
5.7
1.3
9.5
18
5.5
2.0
5.0
to
o
0_3
5.7
a,o
lPoa .nd Oo!.re me..ured .t tx.d bi* and .her.lore repre.ent the pow€r
ourour rv.'l.ble durinr thc reproduct'o. ol !pee<h and mu5 c. Whenaiu*r;ned
sine wrv. ii.Dpli.d to th. .onrrol srid th. birs acrorr thc crthod. r€tit(or will
rerdiu* itielf I . ..roh ol th. ino.d.d .nod. and 3creen-srid .u..ents, This
will re.llt in.pproxin.t.ly lo% rcducrid i. power outplt.
OPERATING CONDITIONS FOR
T\,vO VALVES IN CLASS'AB'' PUSH PULL
(s.e
rir.
2 rnd
3.)
250
250
t30
8.0
2x3l
2 x 37.5
2x l.s
217.5
t6
ll
r.0
3@
3t)0
130
8.0
2x36
2x46
2x1.0
2xll
20
17
1.o
V
v
()
kQ
mr\
mA
mA
mA
v
W
%
Strict quality control and uniformity in the manufacture of the EL37 makes
this tube an excellent replacement for the 6L6, 5881, 1614, and KT66 where clean,
undistorted reproduction and longer life is required. The specialized manufacture of
Nlullard high fidelity tubes, particularly the EL37, assures balanced audio power output
heretofore unavailable in ordinary power output tubes. The EL37 is highly recommended
where true balanced sound reproduction is required.
HEATER
6.3
1.4
lh
LIMITI NG VALUES
CHARACTERISTICS
250
250
-13.s
100
,l3.5
120
13.5
t"
RK
8n
V
V
V
mA
mA
c)
(cathode bias)
kO
(fixed
bias )
v
800
v
400
v
800
v
400
75
V
500 ko
100 ko
25W
IVULLARD RETIVA
"/--;\
'(..o#
)"
TYPE
EL34 ..-
EQUIVALENT DESCR]PIION
-'EL37--,:,!,--- 6L:
:Sii1
PR ICT
Pentode
--.6CA7 - ----.-.--..-Output
Matched Pair, 2-E134
--
output Pei:tr,i.
-- - :
$4.34
-.....,- --..9.75
---.,-5.5+7.95
--EL84
.68Q5 .. - Output Pentode, N,4iniature 2.40
lvlatched Pair, 2-E184
..., 5.80
6267-2729 -. Low Noise, AF Pentode .... --.- 2.75
t*EF86
-- - 2.60
1*ECC81 ,.- I2AT7 --.,--. -RF Double Triode
Low-p AF Double Triode.
2.2A
1*ECC82 .- 12AU7
High-/, AF Double Triode ..--.2.50
1'ECC63---, ,,.12AX7
ECC85 ----.- -.,-.----.- RF Double Triode -...-.-..---- 2.9O
EZ80 -, .6V4
."lndirectly Heated, Full
1.80
Wave Rectiiier, 90 l\4A
EZ81-------- - 6CA4 -,--, lndirectly Heated, Full-------- 2.2O
Wave Rectifier, 150 lVlA
G232..---, -,-- .5V4c - .lndirectly Heated, Full,--. --..2.95
Wave Rectifier,300 MA
*G234 -.-,---- 5U4GA,/B Bantam lndirectly Heated , --,.- 3.50
(ref. spec.) Full Wave Rectifier 250 l\4A
ECC91--..,-,---.6J6-,-,-,-,------RF Double Triode with-.., ...-2.70
Common Cathode
E891,
l\4iniature Double Diode with -- 1.80
6A15,
Separate Cathodes
EC90
6CL
- lvliniature RF Power Triode---- -,- 3.50
EZqO
6X4 -,.., ---- .lndirectly Heated Full Wave-------- 1.70
Rectifier, T0 lVlA
EF94
6AU6 -,--,,-- - - Sharp cut-off RF or AF Pentode-, 2.15
Electron Beam Tuning lndicator-, 3.90
Elil81-,- ----""
KT66-1614
Matched Pair, 2-E137-
CIRCUIT
B
OTHER IMULLARD PREFERRED REPLACEI\IENT TYPES
Mullard Retma
Type Equivalent
Equivalent
EBC9O
EBC91
EF93
EF95
EK9O
EL9O
1
6AT6
6AV6
r.7 5
6BA6
2.10
64 K5
4.90
6BE6
2.20
2.25
6A05
1.7 5
HBC90 12AT6
HBC91 12AV6
HF93 12846
HK90 128E6
HL92 50C5
HY90 35W4
Especially designed and constructed
for
microphonics
* lvlaximum levels specified and guaranteed
Price
1.75
r.70
2.10
2.20
2.25
1.45
lowest hum, noise and