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williamneo

DIY State of Art Grado RA1? Beginner Learn here!

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Put it together already.

 

Some observations:

1) Sound quality is better than if I plugged directly to iPod. But there seems to be a background hissing noise if I use the amp. Don't know if there is some way to reduce it.

2) Volume is not only slightly amplified. Is that supposed to happen?

 

Anything I can do to improve it?

 

How to I get line out from my ipod to the amp? Is there a cable I need to get?

Edited by Sean

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make sure ur gounding is connected properly, e.g pot ground, power gnd and source gnd is connected together. there is a kind of cable with both end is the same like ur headphone plug.

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make sure ur gounding is connected properly, e.g pot ground, power gnd and source gnd is connected together. there is a kind of cable with both end is the same like ur headphone plug.

 

I made sure the grounding is okay already. Before that the hissing was a lot worse and audio was very, very bad. After checking the grounding, much better but the hiss is still there. I read on head fi that it could be because of my headphones having low impedence. And to solve it, we can add this thing called 'R5'. Is that some kind of resistor? Where should I stick it? Other than the hissing, I'm quite happy with the audio quality. Even though the amplification is not very much higher. The sounds come out a lot more crisper and better defined. Can pick out some instruments a little better.

 

Anyway, some photos..

 

IPB Image

 

IPB Image

 

Power Supply

IPB Image

Edited by Sean

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[attachmentid=3965]

Bro add it here! btw your capacitor use wrongly wor for the 4.7uf (aka 470nf) should be Polypropylene type. which has no + or - Sign on the cap de. as for ur power supply there the smaller cap also wrong wor. The power supply there also polypropylene type not Electrolytic type. The bigger cap is correct. If let say your headphone compatible issue then might need to try out different gain. as you can see the 120k ohm resistor right. u can try change it to 90k ohm resistor. so the break down is....

 

1st add the R5 (100 Ohm) to remove the Hiss.

 

after the that u see if you are happy with it a not.

 

IF NOT.... then

 

change the caps and try listen to it, if everything is fine then leave it at it is.

 

if not carry on with the changing of the gain level by swaping the 120k ohm to 90k ohm.

post-4040-1206645906_thumb.jpg

Edited by williamneo

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[attachmentid=3965]

Bro add it here! btw your capacitor use wrongly wor for the 4.7uf (aka 470nf) should be Polypropylene type. which has no + or - Sign on the cap de. as for ur power supply there the smaller cap also wrong wor. The power supply there also polypropylene type not Electrolytic type. The bigger cap is correct. If let say your headphone compatible issue then might need to try out different gain. as you can see the 120k ohm resistor right. u can try change it to 90k ohm resistor. so the break down is....

 

1st add the R5 (100 Ohm) to remove the Hiss.

 

after the that u see if you are happy with it a not.

 

IF NOT.... then

 

change the caps and try listen to it, if everything is fine then leave it at it is.

 

if not carry on with the changing of the gain level by swaping the 120k ohm to 90k ohm.

 

hey! thanks!! I was unable to find the polypropylene type in sls. Ask the uncle they look at me in a funny way :blush:

 

Think I will change the caps first beause I want the true 'gwado' experience. If still got hiss, I will hoot the r5 haaahaa.. Thanks for your advice. Will post updates here soon. Need to go back to SLT..

 

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Hi Sean! this is polypropylene type capacitor. The different is there is no (+) or (-) on it, u can use either direction.[attachmentid=3966]

This cap brought at SLS

post-4040-1206681813_thumb.jpg

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[attachmentid=3965]

Bro add it here! btw your capacitor use wrongly wor for the 4.7uf (aka 470nf) should be Polypropylene type. which has no + or - Sign on the cap de. as for ur power supply there the smaller cap also wrong wor. The power supply there also polypropylene type not Electrolytic type. The bigger cap is correct. If let say your headphone compatible issue then might need to try out different gain. as you can see the 120k ohm resistor right. u can try change it to 90k ohm resistor. so the break down is....

 

1st add the R5 (100 Ohm) to remove the Hiss.

 

after the that u see if you are happy with it a not.

 

IF NOT.... then

 

change the caps and try listen to it, if everything is fine then leave it at it is.

 

if not carry on with the changing of the gain level by swaping the 120k ohm to 90k ohm.

Just a quick question - you mentioned that 4.7uF is equivalent to 470nF. I'm thinking that uF is micro farad and nF is nano farad. If that is the case, there should be 3 decimal places between micro to nano. So isn't 4.7uF = 4700nF?

 

 

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Just a quick question - you mentioned that 4.7uF is equivalent to 470nF. I'm thinking that uF is micro farad and nF is nano farad. If that is the case, there should be 3 decimal places between micro to nano. So isn't 4.7uF = 4700nF?

 

Here's a nice link for conversion:

http://www.electronic-supply.com/capconversion1.htm

 

And so 4.7uF = 4700nF.

 

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ops sorry.... wrong info... got to make a change.. thx heady you are right is 4700nf! dead meat i can't edit my previous post

Edited by williamneo

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Hi Sean! this is polypropylene type capacitor. The different is there is no (+) or (-) on it, u can use either direction.[attachmentid=3966]

This cap brought at SLS

 

Actually, you can't tell from a picture what kind of film capacitor it is. One can only be sure it is a film capacitor. Most probably it is a polyester film capacitor.

 

In SLT, the only polypropylene capacitors I could find were Rifa Evox which are blue in colour. The most well known polypropylene capacitors are Wima which are red in colour but I have never seen them in SLT. I have seen some in Koba which is in People's Park Centre. Koba has a great collection of stuff if you are new to DIY.

 

If you have money to spend, then audiophile tube shops will sell polypropylene caps like Solen etc. For example, Martins and another shop beside it, in Burlington Square which is next to SLS.

Edited by heady

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Actually, you can't tell from a picture what kind of film capacitor it is. One can only be sure it is a film capacitor. Most probably it is a polyester film capacitor.

 

In SLT, the only polypropylene capacitors I could find were Rifa Evox which are blue in colour. The most well known polypropylene capacitors are Wima which are red in colour but I have never seen them in SLT. I have seen some in Koba which is in People's Park Centre. Koba has a great collection of stuff if you are new to DIY.

 

If you have money to spend, then audiophile tube shops will sell polypropylene caps like Solen etc. For example, Martins and another shop beside it, in Burlington Square which is next to SLS.

 

Thanks heady. Yeah it was quite difficult to find the polypropylene caps in SLT. I will check out Burlington Square..

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Went to Burlington Square to get Solen caps today. There were HUGE!! Only came in 400V.

A great, great improvement !! I'm so much happier now with what I'm getting. The clarity is just amazing and it beats the audio coming out of the ipod anytime.

 

My only problem with this is the hissing. There is still a very slight hissing when there is no audio playing. The hissing loudness remains the same at all levels. I've already added the 100 Ohm resistor as mentioned by william but still it does not go away. Don't know what else I can experiment with now. Any suggestions weill be greatly welcomed. My TLE2426 should be arriving soon and I will be testing the virtual ground circuit. Maybe it will help?

 

 

IPB Image

 

Also replaced the cap on the power supply as advised by William

IPB Image

 

 

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Hmm. Your power supply only that one 0.1uF cap? For power, you can place a good electrolytic cap 470uF in parallel to that cap.

 

For the hiss, I think you are using IEMs or sensitive headphones? You can try lower the gain. But the better idea is to build something better. A CMOY is only an exercise in learning to diy and to whet the appetite for bigger things to come.

 

Try building a Mini3.

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