EV44xx amplifier series
This amplifier is custom made in Australia, but there were only some pictures of it. The type number of this amplifier is EV4417 and was used in a cinema for the audio. Sometimes four of these units were used and controlled by the projector.
Text plate type number and other data of the EV4417.
Here the schematic diagram for of this amplifier.
Schematic diagram EV4417.
For the pictures. Thanks to Kieren Davis Australia.
This amplifier was discovered also in Australia by Tim Robbins. After some searches in my old library I found some data about this amplifier. You will see that this design has been used in about all EV44xx marked units. The following photos were sent to me by Tim Robbins. I redrawed the schematic because the original drawings were very bad.
The inside of this amplifier.
Tim Robbins modified his amplifier to a guitar amplifier for his son. Follow the link for the modifications and an explanation how he did it.
After some searching and asking around I discovered that there was something of a system in this numbering.
Here the result of tis investigation. The EV441x where only the power amplifiers, the EV443x amplifiers were the complete amplifiers with tone controls and additional inputs.
The EV4415 and the EV4435 series were reserved for amplifiers with 2 EL36 (6CM5) power tubes.
At the bottum of this page you will find my latest discovery: "The LOWLINE" with ECL86 (6GW8) tubes. Called the EV4438B.
Pictures of this solution are shown here.
Schema of the EV4415.
The EV4435a frontview.
The EV4435a rearview.
The EV4435a topview.
The EV4435a view inside.
Schema of the EV4435(a).
There was also a discovery of an old record player with a built in amplifier of the EV44xx series.
This amplifier was built as by using the chassis of the power amplifier, but when using it with a record player you miss the tone and volume control.
Philips solved this problem by building an extra tube inside the amplifier. They used the same circuit as the complete amplifiers.
Pictures of the recordplayer amplifier. Type number of this amplifier is EV4411. This type number is for me still a mystery !!
The inside of the record player.
The inside of the amplifier.
The preamp built near the tone and volume controle.
For schematic diagram of this amplifier see the EV4431.
The EV4411, the EV4416, the EV4431 and the EV4436a series were reserved for amplifiers with 4 EL36 (6CM5) power tubes.
Frontside of this amplifier with cover.
Backside without cover.
Frontside without cover.
Inside of this amplifier.
Same amplifier, another built.
Schema of the EV4411.
Schema of the EV4431.
The EV4416 and the EV4436a are new discovered amplifiers in the EV series.
Jonn Connolly changed his EV4416, which he got from Steve, with the help of Graham, into a guitar amplifier and was very pleased of the sound.
Front view of the EV4416
Rear view of the EV4416
The EV4436a amplifier
Front side without a cover (EV4436a).
Rear side (EV4436a).
Bottom side (EV4436a).
Output transformer connection.
Schema of the EV4436a.
The EV4417 and the EV4437 series were reserved for amplifiers with 6 EL36 (6CM5) power tubes.
Backside of this amplifier without cover.
Inside EL36 (6CM5) part.
Inside supply part.
Schema of the EV4417.
Schema of the EV4437.
There is also another variant of this amplifier: The EV4437a. This amplifier looks very much the same as the EV4437.
In this amplifier there is a limiter circuit built in. This part is drawn in the schematic diagram of the EV4437a.
Typenumber plate EV4437a.
A picture of the limiter part.
Here some extra data of the outputtransformer.
For the pictures and OT data of the EV4437a I thank Tim Robbins who is the owner of this amp.
The EV4418 amplifier:
From Ken Stone I got the folowing pictures of a modified EV4438a for a special purpose with relais control for a microphone input.
Thanks for that Ken
Front view open.
Inside view, you can see the extra relais for remote perposes.
Rear view, type and serial number.
The EV4438B "LOWLINE 10" amplifier:
Front view open.
Another front view with 2 more potmeters.
Rear view open.
Type plate EV4438B.
Inside the amplifier.
Schematic diagram of the EV4438B "LOWLINE 10".
Maybe there are more types of this design. If I find them I will post them here.
If more info is needed, sent an email to el64xx(@)gmail.com. Email adress without ( ).