HMV 2042 Record Player.

[112stereo]

I intend to keep and use this record player.
We are very much into vinyl and want to use this record player once again.
It looks fantastic and has good styling, however, the workings are in very bad shape.
The deck is toast, motor so rusty and the pinch roller has disintegrated so beyond repair.
Found a Garrard sp25 which I fitted with a magnetic cartridge which I fitted a pre-amp and the whole thing works again, but bass response is very poor.
Can anyone suggest how I can improve the response buy perhaps a modification to the amp ?
The pre-amp is of good quality and designed for this task, the internal amp has had all its caps changed.
The speaker has been upgraded as the original was seized solid.
The amp has plenty of volume and perhaps good in the 60s just doesn't cut it with later vinyl LP's from the 70's and 80's that have better sound.
I know what you are thinking but I really want to make this player worth using again.
Can anyone suggest a solution.

[Chris R]

I note that you are using a magnetic cartridge with a pre amplifier. Does the pre amp incorporate equalisation for a magnetic cartridge? Without it, the sound will be lacking in bass and sound very thin.
That record player usually sounds very good in its original form. I'm not sure what you mean by 70's and 80's having better sound. Many late 50's and early 60's have excellent sound. Very much depends on the equipment used.

Chris R

[Chris R]

I should have asked you what is the impedance of the upgraded loudspeaker. Is it the same as the original? If not there will be a mismatch and the danger that the amplifier could be damaged.

Chris R

[whyperion]

https://www.youtube.com/watch?v=JeIpe6VdNYU

If it is this BSR Deck based unit, I cannot recall this style of player giving out much in the way of bass response, don't forget the tone control will cut the bass from a maximum, not boost it.

Now, carefully increasing the storage value (microfarads) of any capacitor feeding the audio amplifier stage (or coming from it) should increase the bass response, likewise any capacitor to earth can be reduced in capacity to reduce the bass frequencies being 'lost'. This assumes the capacitance of the cartridge is not such that the required frequencies are not getting out at all. It may just be that the existing capacitors are out of their proper range, check the schematic which should be available from the download site here first, maybe correctly rated with better tolerances might be all that is needed, or just a relatively small change, as simple as adding a small additional capacitor (of same voltage rating) into the audio out side of the bass variable resistor, assuming that variable resistor is again of correct type (log scale ?) it might be in manufacturing a component was not available and a near type might have been used, so a better one, to the circuit design, or an improved design might be worth trying.

[112stereo]

The replacement speaker is 8 ohm same as the original and the pre-amp is designed for this type of cartridge.
As I said before the deck has been replaced with a Garrard SP25.
I tried connecting a 8ohm tower speaker to it which sounds really good on my technics amp and it still sounds uninteresting.
All the musical instruments can be heard they are just don't have much body, checked the cartridge wiring and its correct according to the Internet.
I haven't done any component changes to the input circuit perhaps a set of new caps would help, although both bass and treble controls work they just don't improve the sound very much.

[112stereo]

This is the 1st stage of the amp.

[Chris R]

Just another thought.
I wonder if the two channels are out of phase. You could try reversing the connections to the cartridge on one channel. Can I assume that this is a stereo preamp and that the outputs are commoned at the input of the amplifier?

Chris R

[Edward Huggins]

I think doing what you are trying to do e.g. different deck, MM cartriidge, stereo preamp, the pre-amp PSU - is going to affect the performance of what is a fairly good (by portable record player standards) mono amplifier and largish speaker. Far better to restore it to what is was designed to be, rather than in trying to "upgrade" it to something that it can never be.

[112stereo]

Yes it is a stereo pre-amp and yes the inputs are connected together.
Just tried reversing the connections it did change things slightly but for the worst.
Going to try changing a few caps as whyperion suggested.
As a guide which ones should I try ?

[112stereo]

Just to clarify why I am going to all this trouble, we go to vinyl sales locally and this record player draws people in just to look at the cabinet and when we play music from the 60's even more come.

We always ask for a power point for which we pay a bit extra but it certainly helps record sales. They are not interested what's inside just the music we play and the cabinet. Hence I just want to improve the quality of sound by what ever means.

[Chris R]

I think I have to agree with Edward. If the amplifier is working OK, it should produce quite decent sound for a record player.
More thoughts :
Can you try to feed in a suitable music signal via the 'Radio' or 'Tape' inputs. That would eliminate problems with the cartridge and preamp.
Check that the DC voltage is 24v after the rectifier. These rectifiers can deteriorate.
You could try replacing some of the electrolytic capacitors which may have gone low/leaky ( C2, C3, C11 & C13 ). If there is excessive hum when the volume is turned down, C8 and C12. The other capacitors on the board are quite unlikely to have become faulty.
I'm sure you will get there in the end!

Chris R

[112stereo]

Thank you everyone for your help and advice, it's given me plenty to go on.
At least I can still use it I just want to improve it.
It was in a terrible state when I got it, for free, that's how I can spend so much time on it.
Everything you have said I will try and incorporate.

[nicam49]

Hi, let us know how you get on!
Certainly Chris R's suggestion in post #11 of feeding music in thro' the other inputs to see if the bass response improves, to eliminate it being the preamp and cartridge is a (ahem) sound one!
That youtube clip shows the same r/c with quite decent sound, so....

[GroovyG]

Just to clarify, and picking up ChrisR's comment in post #7:
- you have a stereo cartridge
- each channel of the cartridge is connected to individual pre-amp input
- polarity of these connections is correct
- the channels are connected together at the output of the pre-amps, this going to main mono amplifier input (depending on circuitry of pre-amp output stage, might need a resistor in each leg to prevent unequal signals here pulling the opposite output around)
Perhaps I'm misreading, but sometimes the devil is in the detail.

Originally Posted by 112stereo

Yes it is a stereo pre-amp and yes the inputs are connected together.
Just tried reversing the connections it did change things slightly but for the worst.
Going to try changing a few caps as whyperion suggested.
As a guide which ones should I try ?