Pioneer SX-1000 TD Dead Ceramic Phono Input

[vortalexfan]

Hello everyone, I just recently bought myself a house that I just finished moving in and unpacking and getting everything except my workshop setup like I want it including my music/listening room.

I was wanting to listen to some records on my great-grandfather's old Motorola
Component Record Changer that dates to 1975 (its a Motorola Badged BSR Record Changer that still works remarkably well considering) and I had the record changer hooked up to the ceramic phono input (because its a low voltage ceramic cartridge @ .5 volts output voltage, and the receiver's Ceramic phono input according to the service data is rated for 51 mV max which should be still within specs of a .5 Volt cartridge which should be able to drive it reasonably without overdriving it.

But when I play a record through it, its completely dead silent, not even a hiss at full volume and I do have it in phono mode with Phono 1 seleted at the Phono input selection toggle switch, and when I hook it up through the Magnetic cartridge input and select that it plays fine albeit its distorted
because its being overdriven, the weird thing is that it was working fine before I moved the receiver to my new house...

Any ideas as to why this unit's ceramic phono input stage would just suddenly die?

Thanks for your help in this matter.

P. S. I do have a schematic for this unit if you need it that I can upload.

[Electronic M]

Hopefully you didn't blow the input...you say the input is rated for 51mV=.051V, but you connected a .500V cartridge that would feed it 10x it's rating... unless you misreported those numbers the cartridge should be too strong for the input.

Does the input selector have 2 different phone positions for the 2 inputs or is there a switch somewhere that selects which is the active phono input? If the latter have you verified that switch is in the correct position and toggled it between the two to clear tarnish from the contacts?

[vortalexfan]

Originally Posted by Electronic M

Hopefully you didn't blow the input...you say the input is rated for 51mV=.051V, but you connected a .500V cartridge that would feed it 10x it's rating... unless you misreported those numbers the cartridge should be too strong for the input.

Does the input selector have 2 different phone positions for the 2 inputs or is there a switch somewhere that selects which is the active phono input? If the latter have you verified that switch is in the correct position and toggled it between the two to clear tarnish from the contacts?

Well I'm not really sure what the voltage rating is as the only copy of the original manual I have for the receiver is a poorly scanned copy of the original paper manuals that I got from HiFi Engine several years ago, so its hard to say what the numbers really were, but I was putting in what it looked like to me, unless there was a decimal point somewhere I wasn't seeing.

Yes the receiver has a Toggle Switch for "Phono 1" and "Phono 2" as it has the capability of having 2 different record players hooked up to it, (the ceramic phono input runs off of the "Phono 1" position on the phono input selector toggle switch which is what I was running it on.)

Oddly enough I took the receiver apart monkeyed around with it (checking all of the boards associated with that portion of the receiver for bad caps and cold solder joints on the wire connections and also replacing some burned out dial lamps) and then put the receiver back together and hooked everything back up and sure enough the ceramic phono input started working again.
Go figure.

[vortalexfan]

OK So here's the odd part about all of this, right after I fixed the ceramic phono input the record changer I was using (the previously mentioned Motorola rebadged BSR Component Record Changer that used to be my great grandfather's) sounded absolutely horrendous when I tried playing an old Columbia Masterworks Record that had pipe organ, 4 4-part choruses and a brass ensemble performing the music of Giovanni Gabrielli in San Marco Cathedral in Venice Italy, a recording dating to the 1960s with the famed organist E. Power Biggs at the helm (the organ console.)
The higher registers of the soprano voices of the Texas Boys Choir members who were performing the soprano parts of the vocals sounded super shrill and distorted.

So I out of curiosity tried out my old Zenith 2G Record Changer (that was salvaged from an old Console Stereo a while back) and hooked it up, and the record played fine on that record changer so I'm wondering if the suspension was starting to go on the cartridge on my great-grandfather's old record changer (even though it was a NOS ElectroVoice Tetrad Cartridge that I installed in the unit after I got it.)

[zeno]

If the cartridge was an OEM Tetrad the color on the socket
indicates the output. Tetrads were known to go int often. We
kept all the colors in stock.
You could also try the AUX in or tape in & see how it sounds.
Also the phono in #1 & #2 should both be for magnetic cartridges
with a switch for ceramic on one of them IMHO.

73 Zeno
LFOD !

[Electronic M]

Have you successfully used that cartridge with that amp in the past? If you haven't, then test the cartridge on an amp you know it works well with and see how it does.

If you did read the illegible documentation correctly and the cart is 10x the designed input level of the amp that mismatch could easily be the cause of the distortion.

[vortalexfan]

Originally Posted by zeno

If the cartridge was an OEM Tetrad the color on the socket
indicates the output. Tetrads were known to go int often. We
kept all the colors in stock.
You could also try the AUX in or tape in & see how it sounds.
Also the phono in #1 & #2 should both be for magnetic cartridges
with a switch for ceramic on one of them IMHO.

73 Zeno
LFOD !

Phono 1 (up position on the switch) is for both MAGnetic and CERamic phono input and Phono 2 (down position on the switch) is for MAGnetic only (I'm using the exact wording in the owners/service manual.)

[vortalexfan]

Originally Posted by Electronic M

Have you successfully used that cartridge with that amp in the past? If you haven't, then test the cartridge on an amp you know it works well with and see how it does.

If you did read the illegible documentation correctly and the cart is 10x the designed input level of the amp that mismatch could easily be the cause of the distortion.

I'll upload the schematic and you can be the judge for yourself.
But I do know that the Magnetic input voltage looked like 21 mV at first until I saw that the magnetic cartridges were never rated any higher than .5 V so then I blew up the schematic to about 175% and then sure enough the number had a decimal between it (it was 2.1 mV not 21 mV) so it could very well be that the ceramic output voltage number I was seeing was 5.1 mV not 51 mV (or a typo in the schematic).

[Electronic M]

it looks like 51mV...then again that scan has all the clarity and resolution of the average bigfoot sighting image. 5.1mV would be even worse as the phono cartridge would then be 100x the level the stereo input is rated for...

[vortalexfan]

Originally Posted by Electronic M

it looks like 51mV...then again that scan has all the clarity and resolution of the average bigfoot sighting image. 5.1mV would be even worse as the phono cartridge would then be 100x the level the stereo input is rated for...

Could it still be a typo but maybe it was meant to say 1500 mV instead of 51 mV?
It would make more sense for it to of been a typo and for them to of meant to type 1500 mV (1.5 V, which is what some of your ceramic and later crystal cartridges put out voltage wise) with the number 51 because with Japanese being read and written right to left instead of left to right like English is, the person who typed up the schematic might of accidentally tried typing in Japanese rather than in English reading style and forgot to correct it (hence 51 which would read as 15 in Japanese.)

Or going down that same typo rabbit hole perhaps it was meant to say 1.5 V rather than 51 mV (again same concept as the previous point except that they forgot the decimal, inverted the 5 and the 1 (rather than 1.5 they put 51 because they accidentally reverted back to typing in Japanese style of reading, or was just typing too fast and didn't pay attention to what they were typing and accidentally put the "m" in front of the V, when it was supposed o be just a "V". )

I'm asking because the known line level inputs like the AUXilary input and the Tape Monitor inputs (which are line level inputs) are marked 200 mV on the schematic.

[zeno]

This is what you need.
https://www.google.com/url?sa=t&rct=...r-9YnAHlEq0HFC

Inputs dont make sense. There has to be a switch to put it into ceramic.
It needs to go in after the phono preamp stage.
Magnetics have very low output. If you use a mag on ceramic you will barely
hear it. & vica versa if you use a ceramic on a magnetic input it will
blast you out of the house & be distorted. Thats why separate pre amp
are sold for computer & upgrades.

Zeno
LFOD !

[Electronic M]

Originally Posted by vortalexfan

Could it still be a typo but maybe it was meant to say 1500 mV instead of 51 mV?
It would make more sense for it to of been a typo and for them to of meant to type 1500 mV (1.5 V, which is what some of your ceramic and later crystal cartridges put out voltage wise) with the number 51 because with Japanese being read and written right to left instead of left to right like English is, the person who typed up the schematic might of accidentally tried typing in Japanese rather than in English reading style and forgot to correct it (hence 51 which would read as 15 in Japanese.)

Or going down that same typo rabbit hole perhaps it was meant to say 1.5 V rather than 51 mV (again same concept as the previous point except that they forgot the decimal, inverted the 5 and the 1 (rather than 1.5 they put 51 because they accidentally reverted back to typing in Japanese style of reading, or was just typing too fast and didn't pay attention to what they were typing and accidentally put the "m" in front of the V, when it was supposed o be just a "V". )

I'm asking because the known line level inputs like the AUXilary input and the Tape Monitor inputs (which are line level inputs) are marked 200 mV on the schematic.

I agree the schematic is a little off.

But as someone who took a Japanese language course I can say your explanation is slightly wrong. Their page order (as well as comic bubble and newspaper column order) is backwards from ours, but the characters in their words/sentences read left to right (when not arranged vertically which is still common). Over a century ago they used to read their words/sentences right to left, but I doubt retirement age guys were designing solid state amps in the 1970s.

[vortalexfan]

Originally Posted by zeno

This is what you need.
https://www.google.com/url?sa=t&rct=...r-9YnAHlEq0HFC

Inputs dont make sense. There has to be a switch to put it into ceramic.
It needs to go in after the phono preamp stage.
Magnetics have very low output. If you use a mag on ceramic you will barely
hear it. & vica versa if you use a ceramic on a magnetic input it will
blast you out of the house & be distorted. Thats why separate pre amp
are sold for computer & upgrades.

Zeno
LFOD !

I posted the schematic, and excepting for the input voltage values listed on the schematic its exactly how my stereo receiver is wired up, there is a toggle switch on the front panel that says "Phono 1" (Top Position) and "Phono 2" (Bottom Position) and the top position ("Phono 1") is for either Ceramic/Crystal Cartridge input or Magnetic input, and the Bottom Position ("Phono 2") is Magnetic only, this toggle switch is in addition to the mode switch which switches between AM, FM Mono, FM Stereo, Phono, and Tape Head.

[vortalexfan]

Originally Posted by Electronic M

I agree the schematic is a little off.

But as someone who took a Japanese language course I can say your explanation is slightly wrong. Their page order (as well as comic bubble and newspaper column order) is backwards from ours, but the characters in their words/sentences read left to right (when not arranged vertically which is still common). Over a century ago they used to read their words/sentences right to left, but I doubt retirement age guys were designing solid state amps in the 1970s.

OK, but I'm still thinking that the "51" was supposed to be "15" (and maybe instead of reading as mV it was supposed to read as 1.5 V, but either way its working fine now.

[zeno]

Lets look at a few cartridges.

Pickering V15-AT2 AKA Pickering grey. The most common magnetic
used in add on and built in TT's in the 70's.
Tracking 2-5 G
Output 4.4 mv
resp 20-20K

Tetra is almost imposable to nail down due to shear numbers
BUT outputs start at 100 mv & go over 300. Most are custom built for specific models, not for general add on TT's.

SO a ceramic has 20 times MORE ++ than mags. Thats why it has to have a switch, most likely on the back to make it work right.

73 Zeno
LFOD !