|
Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
|
Thread Tools |
18th Nov 2017, 4:43 pm | #1 |
Triode
Join Date: Oct 2017
Location: Stowmarket, Suffolk, UK.
Posts: 11
|
Fidelity HF41
Hi
I've got a Fidelity HF41. I need help to Identify what amp would be used in this Machine, as I can not find any info. |
18th Nov 2017, 5:58 pm | #2 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,636
|
Re: Fidelity HF41
There seems to be little information about this player, even though thousands must have been made. As far as I can see, it was a basic two valve design, similar to most players of this type. The cartridge and stylus also appear to be missing, although it's quite probable that it would be faulty by now.
|
18th Nov 2017, 6:11 pm | #3 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,293
|
Re: Fidelity HF41
Although looks like a transistor model, I think it's a valve unit using UL84/UL85 and the was the last Fidelity made using valves. To be sure, you can easily check to see if it has any hum when the volume is on full and if it gets warm after after 3 minutes. You are clearly going to need a cartridge for this. If you are planning to restore this and use it, what experience do you have of repairng these old players? If valved, this will have a"live" chassis.
__________________
Edward. |
18th Nov 2017, 6:15 pm | #4 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
|
Re: Fidelity HF41
Can you post an internal picture of the amplifier chassis (or board) ?
As Bill says there seems to be little info on this model. However, it is possible it is not a valve amplifier. By the time Fidelity got to model HF37 they were using a discreet transistor amplifier and models HF42, HF43 and HF45 use an integrated circuit amplifier. |
18th Nov 2017, 6:26 pm | #5 |
Triode
Join Date: Oct 2017
Location: Stowmarket, Suffolk, UK.
Posts: 11
|
Re: Fidelity HF41
Hi
There is no amplifier chassis just screw holes on the back of the front panel. |
18th Nov 2017, 7:43 pm | #6 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,424
|
Re: Fidelity HF41
Even if you can identify the amp you will be very lucky to find one. You could fit a transistor or IC amp plus PSU and new cartridge to get it working but I would make sure the deck is in working condition or can be made so before doing any other work on it.
__________________
Frank |
18th Nov 2017, 8:21 pm | #7 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
|
Re: Fidelity HF41
I hadn't understood from your first post that the amplifier was missing completely, that does make things rather difficult.
|
18th Nov 2017, 9:21 pm | #8 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,293
|
Re: Fidelity HF41
Aghh - I didn't twig this either! I suggest you fit a Mono IC module and that will allow you to use a (still available) medium output cartridge.
__________________
Edward. |
20th Nov 2017, 8:48 am | #9 |
Triode
Join Date: Oct 2017
Location: Stowmarket, Suffolk, UK.
Posts: 11
|
Re: Fidelity HF41
I have got a UL84/UL85 valve amp , So I think I will fit that valve amp and change the speaker as its only 3 ohms . Sound better than transistor amp.
Thanks |
20th Nov 2017, 9:47 am | #10 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,424
|
Re: Fidelity HF41
Why change the speaker, your UL84 amp was probably designed for 3 ohms. Not sure it will sound better than a transistor amp, the single pentode valve amps were not known for quality. You will also require an expensive high out put cartridge.
A UL84/UY85 amp will probably be live chassis, if you go down that route build in to the player all required safety features to eliminate any possibility of electric shock.
__________________
Frank |
20th Nov 2017, 10:29 am | #11 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
|
Re: Fidelity HF41
i Frank
I don't think it has been established that the original amplifier was a valve type and given that Fidelity had gone for a transistor amp by the time the HF37 came out the chances are it was a transistor or IC amplifier. |
20th Nov 2017, 10:50 am | #12 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,515
|
Re: Fidelity HF41
Perhaps not as "discreet" as the amp in this HF41
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
20th Nov 2017, 12:29 pm | #13 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,293
|
Re: Fidelity HF41
If I was wrong in my original surmize that this was valved and it is actually a transistor model, then the OP needs to check straight away that there is a 90V tap on the BSR motor to provide the valve heater voltage. The speaker will need to be 3 ohms, but there might be room for a bigger one e.g. 8" x 5". However, the overall limiting factor will be finding a high-output (and now very expensive) cartridge.
__________________
Edward. |
20th Nov 2017, 1:01 pm | #14 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,424
|
Re: Fidelity HF41
Hi Colin,
There is a lot of unknowns with this, valve or transistor but like you I would think semiconductor of some sort. I got the impression that vectraman just had a spare valve amp available and was going to fit that, that’s ok as long as he makes the live chassis safe, if he doesn’t know how to do that it is a major problem. A small semiconductor amp with a transformer PSU and medium output cartridge is the way I would sort it out. What do you think?
__________________
Frank |
20th Nov 2017, 2:03 pm | #15 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
|
Re: Fidelity HF41
Yes, that would be the easiest way to proceed. It is not clear if the speaker is still in the player or not. Either way the speaker used will have to have a suitable impedance to match the amp of course.
|
20th Nov 2017, 5:41 pm | #16 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,636
|
Re: Fidelity HF41
This old eBay auction indicates that it's valve, although that can't be said to be definitive. Has any member come across one in the past, there must be quite a few knocking about?
http://ebay.net.ua/catalog/show/121518194606/ |
20th Nov 2017, 6:09 pm | #17 |
Heptode
Join Date: Jul 2012
Location: Derby DE1, Derbyshire, UK.
Posts: 626
|
Re: Fidelity HF41
Hi,
yes i looked at that to bill, interesting, i wonder if they just did that as a one off, using a UY85 and a UCL82 valve, and used a medium output cartridge something like an X3M. The reason it made me think that, is beacuse the deck is early 70's style, and they may of just been using up serpluss parts at the time. But the thing is, if the amplifier is missing who knows if that is the correct deck, the key to that maybe as others have said, is there a 90v tap on the motor unit? (not much info on it) Paul. |
20th Nov 2017, 7:12 pm | #18 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,293
|
Re: Fidelity HF41
Well, before I say I may have been correct all along, I will say that there were transistor versions of the earlier Fidelity HF35 which orginally used two valves. This transistor variant was chassis built (no ICs) almost like the valved version.
__________________
Edward. |
20th Nov 2017, 11:38 pm | #19 |
Heptode
Join Date: Jul 2012
Location: Derby DE1, Derbyshire, UK.
Posts: 626
|
Re: Fidelity HF41
I don't think you assumed anything wrong edward, it's just that theres very little information on this unit, you were quite correct in everything you gave in your input
Paul. |
21st Nov 2017, 12:25 am | #20 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
|
Re: Fidelity HF41
One way to determine if its a valved or transistor model is to look at the motor and see how many wires it has.
If it has three wires then it was made for a valved model, the third wire feeding the valve heaters, if it has four wires then its a transistorised model. In this case the motor also acts as a transformer, the two white wires being the supply to the amplifier. |