** Hi all,

speaking of UK Vintage Hi-Fi, a Rogers Cadet II system turned up for repair this week. Three units in a cardboard box - main amp, control unit and phono pre-amp. See pic of similar system:

http://lab.sekaimon.com/img/fetch/i/321656407324

There was a little rust on the tops of the units suggesting storage in a garage for some time, the white plastic buttons on the push switches had disintegrated and the front of the control unit was discoloured. OTOH, the large can electros had been replaced and all the valves were Mullard made in UK.. I doubt if they were the originals.

Both power amps were dead or good as. A check with a multimeter showed that many composition resistors had gone high value or were open. Once they were replaced, good operation was restored. The control unit needed similar attention while the RIAA pre-amp was OK.

I guess the ECL86s are a bit worn as the most power I could get was 6.5 watts into 15 ohms. At 4 watts, THD was around 0.2%.

Internal wiring is very neat with no PCB or tag board used, components are strung between pillars fitted to the chassis and travelling through in case of the two pre-amps. Not the fastest way to build something, but it sure makes repair easy.

Is the Cadet II "a poor man's Leak" or is that too harsh ?? Making the phono pre-amp an option surprises me, limiting use to Ceramic PUs and radio tuners for most buyers.

The ECL86 valves are no longer made and only NOS and used examples are on offer - at rather high prices. Might be smart to rewire the main amp to use EL84s and add a pair of ECC83s on the chassis. Replace the selenium rectifier with a silicon bridge and you could get 10 watts per channel.



..... Phil

This is very odd. I have a Cadet II here its all in one unit and the riaa
stage is controlled by anoctal plug in device in one side of the chassis.
IE Ceramic or Magnetic.
Most of the issues mine has are around hum, some crackling on some of the
valveholders the preamp seems worse, and some cosmetic issues and it needs a
new switched volume control. Did they then make these uniits as seperates as
well as integrated. i bought this new in the mid 1960s and its present use
is on a pc as an amp.
My valves are Mullard and have never been changed either. It does keep the
room nice and warm so I doubt if its that efficient. the light on the front
panel needs a clout from time to time to make it come on. The front mounted
Didn socket for tape is a bit mangled now, but its rivetted on and needs to
be drilled to get it off.
The way the amp is split at the tape socket is a bit odd also the mono
button on radio seems to just use one of the aux in sockets not the other
one.
These sockets need a bit of tlc.
The rear mounted mains sockets wer in a previous thread on here.
Still after all this time it was obviously built to last. The two filters
on the front panel seem a bit pointless.
It was used for many years to drive a pair of Denton speakers which are
still in use in a front room and still sound quite reasonable.

Big play was made in the amp of it having ferrite cored speaker tansformers
and several impedence terminals for different speakers.

Last time the power was checked the output was similar to yours, though it
claimed it was 12.5 watts per channel. Intrigingly it seems to be able to
run very loud and sound nice, so I suspect other amps watts are poorer
quality ones than these are grin.

I alway remember an amp made by a couple of Sinclair z12s which on the
surface sounded pretty good but there was a weird overhang caused by the
crossover effect of germanium transistors changing with local heating one
supposes. On tests of course it looked good, but as we all know ears are
not test instruments.
Brian

--
----- -
This newsgroup posting comes to you directly from...
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Blind user, so no pictures please!
"Phil Allison" wrote in message
...

** Hi all,

speaking of UK Vintage Hi-Fi, a Rogers Cadet II system turned up for repair
this week. Three units in a cardboard box - main amp, control unit and phono
pre-amp. See pic of similar system:

http://lab.sekaimon.com/img/fetch/i/321656407324

There was a little rust on the tops of the units suggesting storage in a
garage for some time, the white plastic buttons on the push switches had
disintegrated and the front of the control unit was discoloured. OTOH, the
large can electros had been replaced and all the valves were Mullard made in
UK. I doubt if they were the originals.

Both power amps were dead or good as. A check with a multimeter showed that
many composition resistors had gone high value or were open. Once they were
replaced, good operation was restored. The control unit needed similar
attention while the RIAA pre-amp was OK.

I guess the ECL86s are a bit worn as the most power I could get was 6.5
watts into 15 ohms. At 4 watts, THD was around 0.2%.

Internal wiring is very neat with no PCB or tag board used, components are
strung between pillars fitted to the chassis and travelling through in case
of the two pre-amps. Not the fastest way to build something, but it sure
makes repair easy.

Is the Cadet II "a poor man's Leak" or is that too harsh ?? Making the phono
pre-amp an option surprises me, limiting use to Ceramic PUs and radio tuners
for most buyers.

The ECL86 valves are no longer made and only NOS and used examples are on
offer - at rather high prices. Might be smart to rewire the main amp to use
EL84s and add a pair of ECC83s on the chassis. Replace the selenium
rectifier with a silicon bridge and you could get 10 watts per channel.



..... Phil

Brian Gaff wrote:


This is very odd. I have a Cadet II here its all in one unit and the riaa
stage is controlled by anoctal plug in device in one side of the chassis.
IE Ceramic or Magnetic.


** What you have is a Cadet III, made primarily as an integrated amp but also made as a separate amp and control unit.




Big play was made in the amp of it having ferrite cored speaker tansformers
and several impedence terminals for different speakers.


** Ferrite cores in a valve output tranny ???

As Eliza Doolittle once cried - " not bloody likely".




..... Phil

Well It has II on the front of it, and indeed has ferrite cored
transformers and does sound nice so who knows the weirdness of uk
manufacturers of the period and their branding.
Since I've had it from when I could see, I should know what its called. I
have somewhere a service manual for it, but have no idea just where these
days!

In its early days it needed a new balance pot, but now the mains switched
volume is held together with glue and duct tape but still works very well.


It does put into perspective the planned self destruction of modern
equipment though. A Marantz amp from the mid 80s that sounded good now has
a fault where the mode switching is very confused and the tone controls seem
to work weirdly. I had a Pioneer receiver that ate dial lights and went
intermittent in its fm tuner and the dial string broke. My current Denon
from the 90s is doing better but I'e had to take the speaker relay cover
off so I can occasionally clean it when the channels start to disappear due
to dodgy contact aging.

I did have a very nice rather oddly named (Memorex) receiver built to the
din standard ie no phonos that was very good until one day it put 30 volts
dc through a loudspeaker and melted it.
So much for fault protection.


As for CD players, well...
The only one still without issues was made by Philips in 1983, but nowadays
is so slow at moving to tracks its painful. I fancy making the optical
stuff less massy and faster has just made them wear out faster.
My Marantz will only play cds when it feels like it and I'm now using a
cheapo Panasonic dvd player instead and it actually sounds better
That is progress.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Phil Allison" wrote in message
...
Brian Gaff wrote:


This is very odd. I have a Cadet II here its all in one unit and the riaa
stage is controlled by anoctal plug in device in one side of the
chassis.
IE Ceramic or Magnetic.


** What you have is a Cadet III, made primarily as an integrated amp but
also made as a separate amp and control unit.




Big play was made in the amp of it having ferrite cored speaker
tansformers
and several impedence terminals for different speakers.


** Ferrite cores in a valve output tranny ???

As Eliza Doolittle once cried - " not bloody likely".




.... Phil

On 19/11/2016 10:39, Brian Gaff wrote:


I did have a very nice rather oddly named (Memorex) receiver built to the
din standard ie no phonos that was very good until one day it put 30 volts
dc through a loudspeaker and melted it.
So much for fault protection.


Real DIN or just 5-pin sockets?
Doesn't the relevant standard specify high impedance outputs, current drive and low impedance inputs?

--
Eiron.

To hijack the thread, I wonder if there was a connection between Rogers in Catford who made amps
and Rogers in Mitcham, ten miles away, who made speakers.
And CJ Rogers who designed speakers, for that matter. I'd better start googling it.
(Jim Rogers of JR149 fame founded the Mitcham business.)

--
Eiron.

It does on everything apart from pick up inputs of course. I think at least
one was proper din as it did not like long cable runs, reducing treble, but
I don't think I ever actually checked it in that way. Certainly it needed
less to drive its inputs at line level.
I don't know who actually made it in fact.
Obviously like many things the actual name was used for all sorts of things
but mostly for tapes and discs of course.
It was a shame about it dying but there you go, so much for progress.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Eiron" wrote in message
...
On 19/11/2016 10:39, Brian Gaff wrote:


I did have a very nice rather oddly named (Memorex) receiver built to the
din standard ie no phonos that was very good until one day it put 30
volts
dc through a loudspeaker and melted it.
So much for fault protection.


Real DIN or just 5-pin sockets?
Doesn't the relevant standard specify high impedance outputs, current
drive and low impedance inputs?

--
Eiron.

when you top post no one - without scrolling down to read the post and then
back up again to read the answer - has any idea what you're talking about...


On 19/11/2016 18:01, Brian Gaff wrote:
It does on everything apart from pick up inputs of course. I think at least
one was proper din as it did not like long cable runs, reducing treble, but
I don't think I ever actually checked it in that way. Certainly it needed
less to drive its inputs at line level.
I don't know who actually made it in fact.
Obviously like many things the actual name was used for all sorts of things
but mostly for tapes and discs of course.
It was a shame about it dying but there you go, so much for progress.
Brian



--
David Kennedy

http://www.anindianinexile.com

"David Kennedy" wrote in
message o.uk...
when you top post no one - without scrolling down to read the post
and then back up again to read the answer - has any idea what you're
talking about...


On 19/11/2016 18:01, Brian Gaff wrote:
It does on everything apart from pick up inputs of course. I think
at least
one was proper din as it did not like long cable runs, reducing
treble, but
I don't think I ever actually checked it in that way. Certainly it
needed
less to drive its inputs at line level.
I don't know who actually made it in fact.
Obviously like many things the actual name was used for all sorts
of things
but mostly for tapes and discs of course.
It was a shame about it dying but there you go, so much for
progress.
Brian





You may or may not be aware that Brian is blind and uses a reader
programme. Top posting is a major help from us to him, and it is
easier for him to find the top to post his replies.

He is a valued contributor and those of us who are regular members
will do what we can to help him.


--
Woody

harrogate3 at ntlworld dot com

On 19/11/2016 21:41, Woody wrote:
"David Kennedy" wrote in
message o.uk...
when you top post no one - without scrolling down to read the post
and then back up again to read the answer - has any idea what you're
talking about...


On 19/11/2016 18:01, Brian Gaff wrote:
It does on everything apart from pick up inputs of course. I think
at least
one was proper din as it did not like long cable runs, reducing
treble, but
I don't think I ever actually checked it in that way. Certainly it
needed
less to drive its inputs at line level.
I don't know who actually made it in fact.
Obviously like many things the actual name was used for all sorts
of things
but mostly for tapes and discs of course.
It was a shame about it dying but there you go, so much for
progress.
Brian





You may or may not be aware that Brian is blind and uses a reader
programme. Top posting is a major help from us to him, and it is
easier for him to find the top to post his replies.

He is a valued contributor and those of us who are regular members
will do what we can to help him.


I am actually. And, Brian has previously said that he could post in the normal
manner but prefers not to. [At least that was my recollection, if I'm wrong
then I apologise]

--
David Kennedy

http://www.anindianinexile.com