Cartridge experts please help...EV/ Ronette 105-1

[Levente]

Hey Guys,


Quick question as I am stuck...(again)

Old cartridge Ronette 105-1 with XXX needle and a SA-100 needle


I bought an EV Electro Voice 96 hoping that would be a good replacement. Both needles are SA-075

With the new needle, nearly no sound coming out with full weight on, i can not adjust the pressure further...its at the max...

Am I doing something wrong here? The EV has perhaps different pinouts? but reading it would replace the 106 (assumed would do the 105 too?)

105 has output 250mV
106 has output 750mV

That means the EV 96 cartridge wont work at all?

Any advise will be greatly appreciate it.

thanks

[Techman]

Do not increase the tracking weight above that recommended for the cartridge. Increasing the weight has nothing to do with output. What you're doing will wreck the stylus, cartridge and records. You may have already done damage by doing this. There's obviously a fault which you need to investigate.

[Techman]

Just to add - the output of the two cartridges quoted is vastly different. You need to get the pin out correct, guesswork won't do, it has to be correct.

[Levente]

Thanks for the advise...

where shall I start? because of the output differences, should I discard the brand new cartridge I've purchased? the EV?

I just dont understand if the old cartridge "sort of" works, and wiring the same way the new one, why doesnt...

With the old cartridge is, the volume and gain is so high that the volume control only just a fraction up from the 0...and if I touch the metal stylus cartrisge part (its a garrard typical on SP25s) a HUGE LOUD feedback buzz is coming out of my speaker...and there is some voltages in the metal parts...

I have

not sure where to start...followed the 4 pin connections,

pin 1 L ground
pin2 L positive (red)
pin 3 R ground
pin 4 R positive (white)

this is how it was originally connected...inside, all the caps (besides the film caps for the bass/ treble ) were changed...just how it was.

[John10b]

I’m trying to understand your problem. I’m a bit concerned that you talk of volts on metal parts?
You say your getting a good strong buzz when you touch the wires which go to the cartridge. This suggests the amp should be ok.
As Techman says you need to connect the wires to the cartridge correctly, I know this seems obvious but you must get that right.
Cheers
John

[Audio1950]

The pin- outs on the two cartridges may well be different. The Ronette 105 had the channels connected diagonally across the pins, which was unusual. The EV probably follows the usual pattern, which is that the "positive" and "ground" are both on one side of the cartridge (as you look from the back), one above the other. I also have concerns about volts on metal parts?

[Levente]

Originally Posted by John10b

I’m trying to understand your problem. I’m a bit concerned that you talk of volts on metal parts?
You say your getting a good strong buzz when you touch the wires which go to the cartridge. This suggests the amp should be ok.
As Techman says you need to connect the wires to the cartridge correctly, I know this seems obvious but you must get that right.
Cheers
John

Thanks John, sorry if I sounded confusing....voltages are just a couple of volts of not less ( I hope)...it lits up my mains testing screw driver...

I have got this machine scond hand, and took some time to figure out what the previous owner did ( or did not ) on this machine...

sooo...the L+R positives and L/R negatives are together (bridged?) and goes to the volume pot and one single speaker.

The Cartridge is a 4 pin Ronette Stereo 105.

The huge buzz is only when I touch the top of the cartridge aluminum part...if I touch the lever aluminium, I don't get that huge speaker buzz....just a very slight hum..

checked there is an earth wiring and re soldered at the back of the lever and goes to underneath the unit...all seems OK...

I found a previous thread here with some similar wiring, so stereo goes to one speaker L+R but no mention about this huge buzz or hum what I get...

not sure if the cartridge is faulty? I am listing music on the recordplayer as I type but with the old cartridge....funny if I just approach the cartridge with my hand...getting closer to that aluminium part, I already hear a hum...the closer I get the louder it is...

not sure what to do next tho....the volume pot is also reversed....clock wise is decreasing anti clock wise is increasing and the on-off swicth is at the max volume point....weird....

do you have any suggestions?

thanks


PS measured the voltages on the cartridge and the lever arm

2 VAC

and the DC is up and down between -0.08 goes up to +0.08 and down again and up and down in a patters....hmmmm

[John10b]

Not happy with your reply so please turn off and remove Mains lead until we decide your next step
Please tell us what is the Model Record Player you are talking about.
Cheers
John

[Levente]

Thanks John,

It's a Garrard SP25 deck with an early Tempofoon M35 design, ECL86 amplifier.

Attached the schematics...

when I 've started to work on this, replaced C1, C2, C3 as they were (visibly) leaky...the R22 just blown..and the C8 was out of range. These caps were the electrolytics...

Checked the ground wires, cleaned the motor and the wheel bearing.

Now sure what could cause this voltages there and the hum/ buzz...something is not right here..

oh I have not changed the ECL86, looks alright, no sign of any overheating...




one more info...i am testing this with a 4w 8 Ohms...speaker...so loud that the speaker can not really take it...

[John10b]

Ok thanks for all the technical details, I’m a lot happier now, as I can see the amp has a Mains Transformer. I presume from what you already done and said that you have some technical knowledge and understand the dangers of working on such equipment.
May I suggest that you double check the work you have already done.
Cheers
John

[ms660]

Can you post a clearer photo of the connections on the volume control?

Lawrence.

[Levente]

Originally Posted by John10b

Ok thanks for all the technical details, I’m a lot happier now, as I can see the amp has a Mains Transformer. I presume from what you already done and said that you have some technical knowledge and understand the dangers of working on such equipment.
May I suggest that you double check the work you have already done.

Thanks John, i am no way an expert...double checked the soldering al seems alright, ....unless, that the two old 47nF does some weird ...

Originally Posted by ms660

Can you post a clearer photo of the connections on the volume control?

hey Lawrence...thank you again, here it is...

[ms660]

The volume control looks incorrectly wired to me, if I'm looking at the last photo correctly the screening braids from the three screened cables should all be connected to the left hand volume control tag (as viewed in the photo) both the inner wires (white and red) from the two black screened cables should be connected to the right hand tag and the inner wire from the other screened cable that goes to the amplifier board should be connected to the centre tag.

Lawrence.

[Levente]

Originally Posted by ms660

The volume control looks incorrectly wired to me.

thanks Lawrence....I should swap around then...but the AC/DC weirdness in the the cartridge/lever or even in the chassis I assume as it is connected to it is weird...would you recommend to change those film caps here too just like in the old RCA amp in the other thread? I though they are more for the EQ bass / treble...but they could pass some unwanted voltages right?

or test it with another ECL86...?

OR the selenium rectifier is giving up?

[ms660]

Hi I have just amended my last post, connect cables as per that to fix the "reverse volume" first.

Once that is done it would be good to see a photo of the tag strip under the deck that the cartridge wires are connected to and a close up photo of the connecting pin end of the pickup cartridge that you wish to use.

Lawrence.

[Levente]

Lawrence, Thank you so much. I really do appreciate your help...I am telling you the stuff I've learned from you and the help I am getting here is simply amazing....
Thanks....will report back once I have done these work...

Levi

[buggies]

Is that some continental way of drawing a potentiometer?

Looks like the input is permanently shorted to chassis to me...

[Herald1360]

It's weird, but no blob suggests no connection to ground. It may be a stylised way to suggest screened cable.

['LIVEWIRE?']

I can only think that the blob indicates the screen of a lead, the inner core of which is connected to the wiper of P1, otherwise, as buggles says, the input would be permanently grounded.

[buggies]

Looking at the rest of the circuit their blobs seem to be scattered at random!
The other two pots (tone) are depicted similarly but are only wired as variable resistors so look ok.