EML 45B

Description

2A3 Mesh tube

Features

  • The 45B tube is designed to build amplifiers with fully original 45 tube sound, but the 45B is able to do so at more than twice the output power. However the amplifier needs to be modified, or new designed.
  • Without modification, the 45B can be used in every normal 45 amplifier just as well.

High Resolution

About the 45 tube, 45B tube, and how to use it.

The 45B tube resulted from the many conversations I had with my friend Roger Modjeski, who unfortunately passed away in 2020. Roger spend his entire life and career on designing classical tube amplifiers, combining high output power with long tube life.

How to use the 45B instead of the 45.

Guarantee program for first owner.

At EML we have the normal guarantee. In addition to that, the first owner can register the tube within 4 weeks after receival, at the Emission Labs website, to participate in the 5 years guarantee program.

Our Guarantee conditions


Register here for the 5years guarantee

 

EML 45B  Filament Ratings 

Filament Voltage 
= 2.5Volt (AC or DC) 
Tolerance on filament voltage
5%
Filament Current
~ 1.5Ampere
Maximum Time on Stand By (Heater voltage only)
2 hours

EML 45B Capacitance

Grid to Plate
7pF
Grid to Filament
4pF
Plate to Filament
3pF
.

EML 45B Maximum Conditions

Plate Voltage 
420Volt 
Plate Current 
53mA 
Minimum Plate Dissipation
8.5Watt 
Continuous Plate Dissipation
22Watt 
Power Output in Class A 
5.2Watt 
Grid resistor

500k Ohm

EML 45B Factory Test conditions

Plate Voltage 
275V 
Plate Current
36mA 
.

45B Recommended Single Ended operating points.
Bias Method: Auto Bias.

Vb
Ua
Rk
Ug
Ia
Ra
Transformer
examples
P Tube
P
Out
Damp. factor
2nd harm. (%)
Tube
         
Ω
See also note 2, 3, 4, 5
 
331V
275V
1444Ω
-56V
36mA
4k6

LL1663-40mA. 8Ω

9.9W
2W
3.5
4.5%
45, 45M, 45B
Classic RCA circuit
331V
275V
613Ω
-46V
75mA
5k5
LL1620-080
4-8-16Ω
20.8W
2W
6.4
0,72%
.
466V
384
2000Ω
-82V
41mA
9k2
LL1679-055 8-16Ω
15.8W
3.1W
4.6
3.5%
45B only. Note6
466V
384
2000Ω
-82V
41mA
6k5
LL9202-050 4-8-16Ω
15.8W
4W
3.2
4.9%
45B only. Note7
.
495V
408V
1800Ω
-87V
48mA
9k2
LL1679-055 8-16Ω
19.7W
3.6W
5.1
3.4%
45B only. Note6
495V
408V
1800Ω
-87V
48mA
6k5
LL9202-050 4-8-16Ω
19.7W
4.5W
3.6
4.4%
45B only. Note7
495V
408V
1800Ω
-87V
48mA
5k
LL1663-050 8Ω.
19.7W
5.2W
2.7
5.6%
45B only. Note8
495V
408V
1800Ω
-87V
48mA
5k
LL1663-050 8Ω.
19.7W
4.5W
2.7
3%
45B only. Note9
.
Credit: We want to thank our late friend Roger Modjeski, from the company RAM-LABS / Music Reference USA, for doing many detailed measurements on the 45B tube. It was shown, the published maximum distortion and maximum output power in this data sheet was achieved easily. Even so, the 45B seemed capable of doing more as published here. Thank you very much Roger. You will be remembered!

 

45 tube curves

45 tube curves

SPICE Parameters for circuit simulation


SPICE Parameters overview

.

EML 45B Mechanical Data


Ceramic UX4 Base

Size including Socket
(but excluding pins)

145 x 58 mm 

Weight of one tube:
140 Gram

Pin 1: Heater1
Pin 4: Heater2
Pin3: Anode (Plate)
Pin3: Grid

 

Notes