Rebuilding the HF100R Seeburg Amplifier (MR A5-L6) - Some Comments

Fred wrote:

I have been discussing the MR A5-L6 amplifer with some engineers and
they came up with the following recommendations. I wanted to post this
to the group for comments. The direction to the engineers was to come
up with recommendations on which capacitors / resistors / components
were the most critical to replace and/or upgrade to improve the sonic
quality of the amp.

One question. How many years of experience have these engineers had
working with tube amps that play 45's? Or is this all in theory? (OK
that's two questions)

--
Tony

One question. How many years of experience have these engineers had
working with tube amps that play 45's? Or is this all in theory? (OK
that's two questions)

The person I worked with designs and builds Single Ended Triod (SET)
amps using 2A3, 45s, or 300B tubes. These are typically designed to
work with modern equipment. See the www.bottlehead.com for
information on these amps. In terms of years of experience, he's
retired so I'd say 30 years of amplifier design experience. He was
not specifically a jukebox 'expert'. I've built a few SET amps and
listen to 45s, LPs, and CDs.

I think the best solution to my problem would be getting a 200
selection Seeburg library unit and then adding my own amp and
speakers. I just wanted a simply way of listening to a large
collection of 45s. The library units are relatively easy to convert to
stereo.

Hi Fred,

How many records are we talking about here? If you have a large collection, why not transfer the 45's to CD using a computer
with a high quality turntable, preamp and sound card (not a Creative Lab's card)? Then get one of the Sony 300 disk players
and send the output to your high end system. If CD's are too low end for you, transfer at 24 bit 192Khz (or 96Khz) and play
right from your hard drive. There are some excellent cards out there for under $500. Even the 200 selections in a library
unit will get old fast when you consider that most B sides are not great tunes. You'll have to change them often to keep form
getting bored.

Mark
"Fred" wrote in message om...

I think the best solution to my problem would be getting a 200
selection Seeburg library unit and then adding my own amp and
speakers. I just wanted a simply way of listening to a large
collection of 45s. The library units are relatively easy to convert to
stereo.

How many records are we talking about here? If you have a large collection, why not transfer the 45's to CD using a computer
with a high quality turntable, preamp and sound card (not a Creative Lab's card)? Then get one of the Sony 300 disk players

Mark,

I already have one of the Sony 400 Disk CD Jukeboxes that plays MP3s.
I've begun the task of transfering my LPs to CD. I have perhaps 500
LPs and 5000+ 45s. I'm familar with the vinyl to CD transfer process
including post capture processing to remove clicks / pops. The
transfer of 45s is labor intensive. I'm just looking for a way to
play them in batches. I like the MP3 link to the Seeburg 3W1 selector
box that someone sells. Sort of a nice merge of new and old
technologies. Add a small tube amp and a pair of Seeburg tear drop
speakers and you have a cool system that takes up very little space.

On a side note, I did get a nice Wurlitzer 1700 HF yesterday locally.
It was in rather nice condition and came with 102 original records
from the 1960s. It's had two owners since 1954 and both were related.

I own a Seeburg G and a Wurlitzer 1250 that i totaly restored .

In regards to the O3D cartridge i borrowed a new one to see what all the
exitement was about & i was not impressed . I know you need to change a
resistor to use this cartridge .
I found an old Pickering aluminum cased cartridge that fits the Seeburg
it is magnetic and takes small L shaped needles it physical shape is the
same as the redhead but is made in 2 halves & comes apart for servicing
.. no model # on it . This cartridge sounds much better than the O3D or
the redhead . Its loud & has plenty of bass ( enough bass to rattle the
cabinet ) without changing any resistors

Lastly i dont understand why people want to try & force an old piece of
equipment to preform like brand new high end equipment . The machines i
have sound great to me with clear highs and enough bass ... many old
records just never had much bass anyway but with newer records the bass
is fine .
Its an old piece of equipment made to only do just so much . I do
understand making some simple changes like a cartridge or cut off the
AVC because those made quite a nice change in mine
But struggling to change things to squeeze sound that is probably never
going to happen out of the old paper speaker is silly to me .
I guess its just an ongoing hobby for some ?

On the G i tried hooking up a small in line equilizer made for car
stereo use that has 7 slide pots on it . I hooked it right in line on
the RCA plug on the amp to the cartridge and adjusted it and it did make
it sound better as for removing the boomy bass part and extending the
trebble but not enough to really care so i removed the experiment .....
but some of you may want to try it ? it did boost the low bass a bit and
make it sound more modern .

The Wurlitzer 1250 sounds great with a new needle and a good record with
lots of low bass . This machine uses a strange cobramatic cartridge and
tank circuit so nice new needles are a must on it .

Happy juking !

I found the pickering 345-03D is the only cartridge for my 7 1950 jukes. I
still have the redheads and some others but IMO you can't beat the 345
sound.
"Ken G." wrote in message
...
I own a Seeburg G and a Wurlitzer 1250 that i totaly restored .

In regards to the O3D cartridge i borrowed a new one to see what all the
exitement was about & i was not impressed . I know you need to change a
resistor to use this cartridge .
I found an old Pickering aluminum cased cartridge that fits the Seeburg
it is magnetic and takes small L shaped needles it physical shape is the
same as the redhead but is made in 2 halves & comes apart for servicing
. no model # on it . This cartridge sounds much better than the O3D or
the redhead . Its loud & has plenty of bass ( enough bass to rattle the
cabinet ) without changing any resistors

Lastly i dont understand why people want to try & force an old piece of
equipment to preform like brand new high end equipment . The machines i
have sound great to me with clear highs and enough bass ... many old
records just never had much bass anyway but with newer records the bass
is fine .
Its an old piece of equipment made to only do just so much . I do
understand making some simple changes like a cartridge or cut off the
AVC because those made quite a nice change in mine
But struggling to change things to squeeze sound that is probably never
going to happen out of the old paper speaker is silly to me .
I guess its just an ongoing hobby for some ?

On the G i tried hooking up a small in line equilizer made for car
stereo use that has 7 slide pots on it . I hooked it right in line on
the RCA plug on the amp to the cartridge and adjusted it and it did make
it sound better as for removing the boomy bass part and extending the
trebble but not enough to really care so i removed the experiment .....
but some of you may want to try it ? it did boost the low bass a bit and
make it sound more modern .

The Wurlitzer 1250 sounds great with a new needle and a good record with
lots of low bass . This machine uses a strange cobramatic cartridge and
tank circuit so nice new needles are a must on it .

Happy juking !

Have you tried the gold or black aluminum cased Pickering ?