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Technics SL1210 MKII --> Musical Fidelity V90-LPS --> Little Dot MKIII --> Sennheiser HD650 = Sounds like a really badly ripped mp3 !?

post #1 of 15
Thread Starter 

Hi!

 

I´m a new member but have been reading post´s here for a while now. But I need your help with some troubleshooting and finding a solution to my problem.

 

 

I recently upgraded from listning to music through my laptop with my HD650 and a B-tech (really bad) headphone amp to the setup you see above. I inherited a Technics SL1210 MKII player and a lot of LP´s from my father and I wanted to listen to them. So I bought a Musical Fidelity V90-LPS RIAA-amp and better headamp, a Little Dot MKIII to be exact. The Little Dot MKIII works fine with the laptop ( although a DAC would do even more for the sound). But when I installed everything and took the record player for a test run, the sound was hideous! 

 

It sounded like a really badly ripped mp3 playing through a broken speaker or headphone! When I plugg in the old B-Tech headphone-amp the sounds is normal, when connecting my Bose Cinemate II to the B-Tech through it´s line-out, I don´t get any problems with sound. I haven´t tried to connect the Bose system to the Musical Fidelity RIAA-amp yet. But I´m a bit confused why I don´t get it to work as I want to. I emailed David at Little Dot as soon as I discovered the issue and he was really great to respond quickly but I don´t understand he´s answer. He asked me to double check that the RIAA-amp is properly applying the RIAA equalization and bringing up the signal to line level. 

 

How do I do that? I obviously works fine with the B-Tech Headphone-amp. 

 

In my world it should work just fine, because everything is a normal line-in, line-out connection and the level´s should the same. 

 

Do you have any thought´s about the problem and what I can try to do in order get my setup to function properly?

 

 

 

Best Wishes

 

//Andreas

post #2 of 15

Okay, first thing. What cartridge is on the Technics and do you have the Music Fidelity set for MM or MC ?

 

If you have a MM cart and the unit is set for MC it will be way overkill. If you have an MC and it is set for MM, you will have to stress the amp to get signal....

 

So ..more specifics please...

post #3 of 15
Thread Starter 

I have a Stanton D5100 Al-11 and the V90-LPS set to MC, I tried both settings and preferred it to MM. I tried to do some research to find out what kind of pickup it was without any success. The best I could find was, that it´s hard to know wether is a MC or MM. The one that sounds the best is the way to go, that was probably wrong? It´s odd that the B-tech amp sounded nothing like the Little Dot, the only difference between MM and MC on the B-Tech was the loudness. 

post #4 of 15

Okay, first - That is a MM cart and should be set that way.  WAY overload setting for MC and not to mention the loading at 100ohm

 

was the table working/setup when you received it ? Did anyone align the cart , set the tracking weight ?

 

Go back to basics...see my video - it could be the weight got set off, and though it may sound OKAY on one, that doesn't mean anything...

Do other things (line level) work okay with the little dot ?

 

http://www.youtube.com/watch?v=CnskL8Pe6fk&feature=player_embedded

 

 

post #5 of 15

Well that's wrong though. The Stanton is MM so the setting should be set as such. Might not solve problem though.

 

I think you have already done most of this but please confirm so we all all on the same page.

 

Computer disconnected from all audio and switched off.

 

Technics to V90 including ground, Use MM input and setting, V90 to B-tech sounds ok on headphones??

 

Technics to V90 etc etc, V90 to Little Dot, still sounds *****?

 

No   Hurrah

 

Yes Well sensitive pre amps and valves never were the best of mates. Unless you are a guitarist......

 

Over to you..

post #6 of 15
Thread Starter 

Okey, my father was a professional DJ for many years so Im confident that he had the turntable set up the right way. Although after transportation and so I did setup the turntable to the best of my ability, when playing on the bose system it sound normal without a trace of the horrible sound with the headphones using the B-Tech headphone amp. I was successful to eliminate the s-sounds. I have tried both the MC and the MM setting on the V90-LPS and it´s still the same just lower volume on the MM setting.

 

The stylus is a Staton D5100 AL-11 but the cartridge has the marking: Pickering V-15/AT-2. The Little Dot works fine with the laptop, iphone and so on. So there is something between the Little Dot and the V90-LPS. I tried a cheaper cable and the sound got worse.


Edited by AHallestrom - 1/13/14 at 7:10pm
post #7 of 15
Thread Starter 
Quote:
Originally Posted by RonaldDumsfeld View Post
 

Well that's wrong though. The Stanton is MM so the setting should be set as such. Might not solve problem though.

 

I think you have already done most of this but please confirm so we all all on the same page.

 

Computer disconnected from all audio and switched off.

 

Technics to V90 including ground, Use MM input and setting, V90 to B-tech sounds ok on headphones?? YES!

 

Technics to V90 etc etc, V90 to Little Dot, still sounds *****? YES, exactly! 

 

No   Hurrah

 

Yes Well sensitive pre amps and valves never were the best of mates. Unless you are a guitarist......

 

Over to you..

 

 

--- So your recommendation is to get another RIAA-amp that works better with the Little Dot?

post #8 of 15

You don't need a new Phono stage. Unless the stage is BAD which it does not appear it is, the V90 is a VERY good phono stage in its weight class.

 

So Technics to the V90 - RCA's in and ground - RCA's out ---> Little Dot

 

Now all the V90 does in terms of signal is set the phono stage and boost to line level. MM is a must...its not just about HOW LOUD it is.

 

Now the little DOT can take other line level inputs, no issue, right ?

 

Now, do you have computers or routers on the same power line ? DONT..phono stages are very sensitive to this. You need clean lines, this is not like digital music ....

 

Also, looking at the little dot user manual, I see there are gain switches.. I would set them ON ON so that it is 3db gain (less sensitive)

 

Let us know...

post #9 of 15

Not necessarily. If I understand correctly it's the Little Dot that's the problem since the V90 works fine with B-Tech.

 

Actually there probably isn't anything wrong with the Little Dot per se. It's the combination of the Little Dot (valves) and the Musical Fidelity (high gain pre-amp).  with a shared ground.

 

Still just guessing here...but I suspect you might have a ground loop via the shared ground. You have one with the B-Tech as well but  you don't notice because it's not that noisy. It's the valves that are creating the noise.

 

How bad do you want the Little Dot? The simplest thing would be to send that back if you could.

 

Otherwise we have to figure out how to separate the grounds without spending money. Which I think will be tricky.

 

It's also possible that a different phono pre amp might provide better isolation with the Little Dot. Duuno how many people run a TT setup directly into a valve amp but we can hope someone might pipe up with a working combination. If you can it might be worth testing the little dot with a different pre amp (a mates? a friendly shop? rmail order and send it back?). That way we can 100% eliminate a faulty little dot before setting a budget for .getting the combination to work.

post #10 of 15
Quote:
Originally Posted by RonaldDumsfeld View Post
 

Not necessarily. If I understand correctly it's the Little Dot that's the problem since the V90 works fine with B-Tech.

 

Actually there probably isn't anything wrong with the Little Dot per se. It's the combination of the Little Dot (valves) and the Musical Fidelity (high gain pre-amp).  with a shared ground.

 

Still just guessing here...but I suspect you might have a ground loop via the shared ground. You have one with the B-Tech as well but  you don't notice because it's not that noisy. It's the valves that are creating the noise.

 

How bad do you want the Little Dot? The simplest thing would be to send that back if you could.

 

Otherwise we have to figure out how to separate the grounds without spending money. Which I think will be tricky.

 

It's also possible that a different phono pre amp might provide better isolation with the Little Dot. Duuno how many people run a TT setup directly into a valve amp but we can hope someone might pipe up with a working combination. If you can it might be worth testing the little dot with a different pre amp (a mates? a friendly shop? rmail order and send it back?). That way we can 100% eliminate a faulty little dot before setting a budget for .getting the combination to work.


You are not correct on the input. You are probably correct on the ground issue and noise

 

The V90 converts to line level and is no different than a CD ...has nothing to do with tube amps / solid state / irrelevant.

 

But the Phono Stage and Turntable ARE susceptible to ground issues which is why he needs to isolate.

 

His dad is a DJ and should be able to tell him the same thing

 

But bottom line...Turntables, phono stages and TUBE AMPS get along just fine. So please don't propagate myths.

 

Easiet way to test and isolate - Run a long extension cord to the little dot so its not on the same ground line. If it changes, great. No change ? Do the same with the phono stage (leave the rest alone) and run the stage power on an extension to another room.


Edited by arcorob - 1/13/14 at 8:23pm
post #11 of 15
Thread Starter 

My father passed away a few months ago, that´s why I inherited the turntable and LP´s so I can´t ask him. I´m really keen on the Little Dot so I won't return it, but I have everything connected to the same outlet plus the laptop and router. So I´ll try an extension cable from another outlet and test the suggestions you gave me. If that doesn´t solve it, I´ll bring everything to the store where I bought the V90-LPS and try other setups. The gain on the Little Dot is ON ON due to the resistance on the headphones. The manual stated that it should be left in ON ON - setup on headphones like the HD650.

 

I´m at work right now but I´ll try it when I come home and let you know how I´m doing!

 

Thanks for the help so far!!

post #12 of 15

Sincere condolences for your sad loss. I'm sure your late Dad would approve of you checking out his tunes. So we will get it sorted....

 

I hate to write knocking copy but the above suggestion re moving the two troublesome units to different rooms is not so much wrong as totally the opposite of what you should be doing. Not to mention impractical.

 

If our current assumptions prove to be correct (that there is a mismatch between the pre amp and power amp causing a noisy ground loop) you want to keep the grounds of both units as close as possible and the cable runs as short as possible. Plug everything into the same wall socket if you can. Leave the computer out of the equation for the time being. It only complicates the issue. Computer power supplies are also potentially troublesome components.

 

What we think is happening is that the earths on both units are at different potential and connected via the earth on the RCA phono cable. This causes a small current to flow where it shouldn't. Worse, the entire circuit then acts as an antennae picking up and amplifying whatever stray interference happens to be in the vicinity.

 

Mic pre-amps and valve amplifiers are both notoriously prone to this effect. Which is why in professional stage and studio settings it is usual to use balanced cabling. That way you can lift the ground and not break the circuit carrying the audio signal we want to keep clean. We cannot do that in this case because the ground and return share the same wire in domestic unbalanced cabling.

 

Anyone interested in the subject might wish to read this excellent primer on ground loops and cabling.

 

http://www.rane.com/note110.html

 

Ground loops are unpredictable and fickle. Which is one of the reasons they are so frustrating to diagnose and fix. Sooner or later though everyone gets one and it does no harm to learn how to deal with it.

 

Whenever I take my laptop or TTs to a different location I always use an audio interface (pro level DAC with multiple ins and outs all on balanced  connectors) and one of these little units.

 

http://artproaudio.com/artcessories/audio_solutions/product/cleanbox_pro/

 

A really good one with transformers comparable to high end moving coil preamps (yours is a cheaper MC unit without transformers which is why the amp has to work so hard and gets noisy) from the likes of Radial costs ~$500 but this ART is good enough and costs only $50.

 

I'll leave you to it now until you get home. Keep in touch. It's fixable but you are going to have to be methodical.

post #13 of 15

Ronal, you and I are working at cross purposes which only confuses the matter. I did NOT ask him to move the units. I asked him to run a LINE (long extension) to the units to verify grounding issues. This is a common test.

 

If it is grounding, the FIX is not to get ANOTHER phono stage or amp, it is fix the ground issue ...geeze. Your advice is senseless. If your tires go flat after putting air in every couple of days, do you FIX the slow leaks or do you replace the car? You are telling him to replace the car to fix a flat.

 

if and only IF it is not a grounding issue then the PHONO stage becomes suspect.

 

I swear the crap that comes out of peoples keyboards astounds me...

 

AHallestrom....best advice, go HERE and post your question where you can get advice from folks who understand turntable setups because unless I jump in and fight with people giving erroneous help, then you will still have this issue a week from now...

 

http://www.audiokarma.org/forums/forumdisplay.php?f=28

post #14 of 15
Quote:
Originally Posted by arcorob View Post
 

Ronal, you and I are working at cross purposes which only confuses the matter. I did NOT ask him to move the units. I asked him to run a LINE (long extension) to the units to verify grounding issues. This is a common test.

 

If it is grounding, the FIX is not to get ANOTHER phono stage or amp, it is fix the ground issue ...geeze. Your advice is senseless. If your tires go flat after putting air in every couple of days, do you FIX the slow leaks or do you replace the car? You are telling him to replace the car to fix a flat.

 

if and only IF it is not a grounding issue then the PHONO stage becomes suspect.

 

I swear the crap that comes out of peoples keyboards astounds me...

 

AHallestrom....best advice, go HERE and post your question where you can get advice from folks who understand turntable setups because unless I jump in and fight with people giving erroneous help, then you will still have this issue a week from now...

 

http://www.audiokarma.org/forums/forumdisplay.php?f=28


I quit. I am going to turn a blind eye to the turntable posts here at head-fi and stick to the AUNE thread...I can always be reached at audiokarma, same id

post #15 of 15
Thread Starter 

Thank you for your condolances! I think that I have solved the problem, I unplugged everything except the RIAA, Little Dot and turntable from the power strip and also changes settings on the RIAA to MM pickup and it seems to work. One record still have problem ?! but all other records works just fine. I think that the specific record is faulty some how. Thank you for your assistances!! 

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