| Raka |
I've just connected my rb250 rewired with 0.14 solid copper wire. The cartridge is a brand new goldring1042. Sound is very nice, but there is some hum.
I have the earthing wire separate from the signal ground, but as I have no earth connector in the wall socket... I connected to the signal gnd and hum reduced a bit, but not enough.
The wires are routed to the tt back plate, to rca's. Using interconnect cables (shielded) doesn't help.
Has anyone faced this problem before? |
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| sreten |
Hmmm........
Even without an overall ground the amplifier (preamplifier) case
is usually grounded near the most sensitive input, usually this
is the earth post near the MM/MC input.
This problem has started after the re-wiring ?
:) sreten. |
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| Raka |
I changed the cartridge and wiring at the same time, but I fitted again my Blue point, and there were not so much of hum.
It's not toooooooo much, but it can be heard. The output of the cartridge is very high (6.5mV versus the 2.5 of the BP), so maybe this is the problem. |
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| Raka |
Problem solved. It wasn't the rewiring
I changed one interconnect cable and the hum dissapeared. I don't know what's the problem with the cable, but changing it the hum reduced a lot.
I don't have earth pole in my wall socket, so I grounded the case with the power supply GND and it reduced a bit more the hum. Is there any problem with this connection?
Now is not so silent as my CD input, but is fine. |
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| sreten |
| quote: | Originally posted by Raka
I don't have earth pole in my wall socket, so I grounded the case with the power supply GND and it reduced a bit more the hum. Is there any problem with this connection?
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AFAIK the case and power supply ground are usually connected
when you have an overall earth, what is a question of detail is
the actual earth path between the two points.
External grounded equipment is class 1, a 3 wire mains lead is
mandatory. Mains transformer is tested to 1.5kV.
For class 2 a 2 wire mains lead is mandatory (to prevent confusion),
and higher quality insulation construction is required, so called
double insulation standards. Mains transformer is tested to 3kV.
There is no problem connecting the case to signal / PS ground.
:) sreten. |
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| carlosfm |
| quote: | Originally posted by Raka
I've just connected my rb250 rewired with 0.14 solid copper wire. |
Hi Raka!
Long time no see.:)
A little off-topic, but does the arm move freely with those solid-copper wires?:confused:
And what wires are that?
It smells me Cat5 cable.:D |
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| Raka |
Hi Carlos, nice to see you again.I didn't remember you were interested in analog, this is good.
Yes, it moves freely, and the suspension works beautifully now. This wire is very very thin, is not cat5 (=24AWG!!!), it's like hair. I would not use cat5, unless I want a fixed tonearm ;)
It's a wire used for winding coils of small motors, etc. I don't know where to get it in a shop, but I have it from my company. If someone is interested I can send the quantity needed for a rewiring, just for free. |
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| carlosfm |
| quote: | Originally posted by Raka
Hi Carlos, nice to see you again.I didn't remember you were interested in analog, this is good.
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Always been interested.;)
I've never left my vinyl.
| quote: | Originally posted by Raka
Yes, it moves freely, and the suspension works beautifully now. This wire is very very thin, is not cat5 (=24AWG!!!), it's like hair. I would not use cat5, unless I want a fixed tonearm ;)
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That's why I asked.:D
Some confusion I made with the cable's thickness...
Anyway, tonight at 2AM I finished my El Cheapo (MM).:cool:
Gotta ditch my tweaked Nad PP1, because it's useless to tweak more.:D |
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| Raka |
What tt are you using now?
BTW, I'm also using now a scheme based on el cheapo, and working in a ps for the synch. motor. |
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| carlosfm |
| quote: | Originally posted by Raka
What tt are you using now?
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Some 10 years ago I bought a used Technics SL-1610 MKII.
Actually it's quite good, and it has an SME-type headshell, so I have several cartriges and change them (and adjust the arm) in seconds.:cool:
As I tend to stick to my things, I still have this turntable, and I will only change it for something that's a real upgrade (and cheap:eek: ).
The arm is not Rega-league, but the TT is a Rega-killer.
Sorry for the purists (someone will kill me:D ) but I really think that a GOOD direct-drive TT is superior to whatever belt-driven-DC-motor-and-whatever-TT.
Speed stability is fantastic.
Put a good arm on a good DD TT (not practical on mine) and it's a cracker.
The sound I get from my Technics is very good, enough for me and for the cartridges I have.
Bass is amazing, better than many "audiophile" TTs.
:angel: |
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| carlosfm |
Raka, I have a doubt on what you made.
You rewired the arm.
But does that wire go all the way to your phono pre?
Or you've just rewired the arm?
You must have shielded wire from your TT to your pre, or else you'll have plenty of noise. |
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| Raka |
I rewired all the internal wire up to two RCAs I fitted in the tt. In the future I'll rewire until the preamp, but have to think how to make this without disturbing the suspension.
Yes, it's of course shielded, and as you can check in previous posts, there was something wrong with a interconnect cable (shielded). Now is noise almost free and sounds very good to my ears. I have to build another pair of interconnects, and listen again to the Firebird suite by Antal. |
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| carlosfm |
| Last night i heard Neil Young - unpluged.:cool: |
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| Raka |
| Unplugged? Are you going to say that your turntable sounds good when unplugged?:clown: |
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| RetroAudio |
Raka: Am glad you found the solution to your hum problem. I have been curious since you first posted and will keep it it mind as I start to play with my phono setup.
A little off topic, but I think Carlos raises a good point about DD tables, if you don't mind my interjecting. I have a Technics SL-110 that came armless and through lots of searching for other tables and arms, cannot justify switching when high prices are involved. The technics is a cast solid piece of metal that is just built heavy and solid, with a motor screwed onto all that mass for dampening.
Ain't no plinths or wobbly suspensions here,..not that the table wouldn't benefit from an isolation stand however. The speed adjustment takes a bit to warm up, but seems stable with the strobe shortly. After much looking around, I think I'm just going to update the electronics with better components and add some machined metal to really beef it up, such as making the arm board out of solid steel. Forget all the dainty and exotic materials and methods, mass is where it's at for all I care. That principle really hit home when I lived in the machine shop world for awhile.
The bigger, more massive the equipment was, the better cut that resulted. It's what I looked for when buying "lighter duty" equipment for my home shop. If you don't want vibration, don't let it occur to begin with is my philosophy. Yeah, it's all controversial and very subject to debate, but it's just the way I see it. It took awhile for me to come to this conclusion since it's very easy to get taken up with all the hype out there. |
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| Raka |
I've been working on my ps, and sound is very good, don't if as good as a good DD, but good enough (did I say this?) for me.
Not that I want to enter a DD vs BD, I couldn't because I've never listened to a DD.
About the mass, I'm thinking about rebuilding the plinth, with dense wood,but I don't have too much time as leftovers from my music studies (now working on the Choral Fantasy) |
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| sreten |
Discussing low / high mass design design in the same sentence
as belt drive / direct drive is utterly and completely pointless.
:)sreten. |
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| carlosfm |
| quote: | Originally posted by RetroAudio
Yeah, it's all controversial and very subject to debate, but it's just the way I see it. It took awhile for me to come to this conclusion since it's very easy to get taken up with all the hype out there. |
Amen.
:angel:
Raka, you've just finished the PSU. :cool:
Take your time now, enjoy the music.
One of these days you'll gain some courage (and time) to make the plinth.
I expect a Stradivarius-type masterpiece.;) |
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| sreten |
| quote: | Originally posted by carlosfm
One of these days you'll gain some courage (and time) to make the plinth.
I expect a Stradivarius-type masterpiece.;) |
A high mass plinth will have surprisingly little effect on
the sound of a high Q (no foam in the springs) suspended
subchassis design. Should look nice though.......
:) sreten. |
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| analog_sa |
| quote: | | A high mass plinth will have surprisingly little effect on the sound |
At least at frequencies where the springs isolate rather than couple. I have little doubt that the plinth will still be audible.
At the time when i was still a proud L07 owner, struggling to get the wretched thing to play half-decent, i experimented a lot with air isolation. A very soft inner tube sandwitched between two 50mm chunks of slate. It may seem strange but it was clearly audible if the lower plate was slate or something else like mdf. Apparently the inner tube did a decent job of coupling at mid frequencies.
| quote: | | If you don't want vibration, don't let it occur to begin with is my philosophy. |
Good philosophy for the Almighty but us mere mortals don't get such absolute control upon vibration. And throwing mass at the problem is a sure way to get it worse. |
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| sreten |
| quote: | Originally posted by sreten
A high mass plinth will have surprisingly little effect on the sound
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| quote: | Originally posted by analog_sa
I have little doubt that the plinth will still be audible.
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I don't like being quoted out of context :
| quote: | Originally posted by sreten
A high mass plinth will have surprisingly little effect on the sound
of a high Q (no foam in the springs) suspended subchassis design.
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Well IMO your completely wrong.
:) sreten. |
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