ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Finally, got my Beogram 6500 running. I have a MMC-2 on it, rebuilt by Franz-Josef Schulte in Germany. The cartridge is close to the original with a saphire cantilever and nude line diamond needle. After setting up, it worked right away. Sure, I had to find a suitable adapter DIN-to-RCA first.
Sound is okey but there to much noise from the vinyl media, more than any other turntable I have had. Any idea why? Old electrolytics in the RIAA stage? Maybe the rebuilt cartridge is not right?
Roger Gustavsson
Hi Roger - I have a couple of questions to help narrow things down.
First of all - What do you have the 6500 plugged in to? - I'm assuming that it's not a B&O product since you are using an RCA adapter?
You may already know this but the 6500 does have a built in RIAA preamp and as such is designed to be connected to a line-level input (AUX, CD, TAPE, etc.) and shouldn't be connected to a PHONO input that will have its own gain. If you plug this into a phono connection, the sound will have too much gain and will therefor be distorted.
Assuming that you have that connected correctly, can you describe the noise you're referring to? Distortion? Hum? scratching/ popping? Is it out of both channels or just one?
Finally - Had you used the BG6500 with the MMC2 prior to the retip with good results?
Happy to help once we get a little more info from you.
Take care
Greg
Beocenter 9500, Beomaster 6500, Beolab Penta MKII, Beolab 5000, Beolab 3000, Beolab 4000 MKI, Beolab 4000 MKII, Beogram 3300, Beogram 3000, 2X Beolink 7000 RDS, 2X MCP 6500
Hi Greg,
Of course, my Beogram is connected to the line level inputs of my Audiolab preamp.
The noise is from scratching/popping. Both channels are affected.
Neither the BG6500 or the MMC2 were used until sunday.
Some are questioning the built-in RIAA stage, referring to the low supply voltage. The input overload margin may suffer from that.
I have almost fifty years of experience from vinyl replay. My earlier setups never had this degree of sensitivity to scratches/popping.
I also have a BG5500 without built-in RIAA stage. I will try it out with an external RIAA.
Roger
Thanks for the info Roger.
Not really sure why you'd be hearing so much surface noise - I have a couple of non-modified MMC2's on my Beograms and have never noticed anything out of the ordinary as compared to my hi-end reference turntable and phono stage. Perhaps it has something to do with the stylus profile that was used? Is the recommended tracking force the same as the original?
Good call trying the cartridge on the 5500 - At least you'll have an A/B comparison to verify the results.
To your original post, I can't imagine how component-level defects in the BG6500's phono stage would induce a lot of surface noise without also generating other forms of distortion in the music - Of course, I could be wrong but sounds unlikely.
Curious to hear what you figure out,
Greg, I have found out that there is a mistracking or/and overload of the RIAA-stage at high modulations. It could be a combination of the two and even be a mechanical problem of the arm drive. Not sure how to check that. About the chosen Components in the signal path, electrolytic capacitors as frequency determing stages are likely to introduce some signatur on the signal. I am thinking about the output filtering of the RIAA-stage, a low-cut close to the audio range. If an electrolytic is to be used, the normal pratice is to have the cut-off frequency far out of the audio range. Here is a track clearly showing some misbehaviour at 40 seconds (and later too): https://www.dropbox.com/s/kctz41h5bliw3o3/Burglars%20Holiday.wav?dl=0 Roger
Greg,
I have found out that there is a mistracking or/and overload of the RIAA-stage at high modulations. It could be a combination of the two and even be a mechanical problem of the arm drive. Not sure how to check that. About the chosen Components in the signal path, electrolytic capacitors as frequency determing stages are likely to introduce some signatur on the signal. I am thinking about the output filtering of the RIAA-stage, a low-cut close to the audio range. If an electrolytic is to be used, the normal pratice is to have the cut-off frequency far out of the audio range.
Here is a track clearly showing some misbehaviour at 40 seconds (and later too):
Roger - I think I've got this and I could be wrong but based on what you're telling us here (and much respect for your ~50 years of vinyl exp)
Here's what I think - The new cantilever and stylus are longer than OEM and therefor the VTA is way off (not a fun thing to mess w/ on a B&O)
Can u check that when the cart is down that (unconventionally - not that the arm is parallel to the base) that the NCL needle is nearly vertical? If it's raked back then every imperfection will be heard
Went on with the Beogram 5500 plus an external Pro-Ject Phono Box II USB last night, just to see if the turntable is the disturbing factor.
https://www.dropbox.com/s/a2snoyebdlu4lmt/IMG_1607.JPG?dl=0
Same result! It is probably the cartridge. Contacted Franz-Josef Schulte about the mistracking. He suggested I send it back for a checkup.
Cartridge is okey according to Franz-Josef. I will have to look at the mechanical side of the tonearm but I am not sure what to look for. Both my Beogram 5500 and 6500 "feels" the same. There is not much of ridigty to speek about, some play while gripping the tonearms. That must be normal. I will remove the old lithium grease and apply new one to the rails and see what happen. What kind of bearing are there inside the arm housing? Is there anything that need attention?
If the tone- and sensorarms are close to parallel while playing and you don't use an antistatic mat or something similar, thisproblem cannot be caused by the deck or its mechanics.It'll have to be with the record, the cartridge, the tracking force or the amplification.
Martin
Martin,
The arms are parallel. No mat. The tracking force has been checked with an external meter, 1.2-1.4 g as Franz-Josef recommended.
It seems that there are very few adjustments possible on the tonearm. Most dimensions rely on tolerances in the production. I have not checked if the needle of the cartridge is in the correct posistion. The length of the arm tube cannot be adjusted? The mistracking was not there on my former turntable…
RogerGustavsson: The length of the arm tube cannot be adjusted? Roger
The length of the arm tube cannot be adjusted?
No.As you say, there are very few adjustments - in general - on these decks.