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Old 16th September 2010, 06:09 AM   #341
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Yes ,mine is doing frequent duty.

Busy designing the enclosure.
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Old 16th September 2010, 04:07 PM   #342
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Default Phono/Regulator PCB

Hooray!!!!!!!!
My boards arrived today 16th September. They are the ones posted 07/09/10.
Very high quality boards, Quanghao is to be complimented on them, excellent.

I see from an earlier post that ideally the second RIAA capacitor should be 4600pF and that 4700pF is near.
I am using Silver Mica 1% capacitors from Farnell of the following values and part Nrs.
C13-15/C25-27 = 13.5nF = 3 x 3,600pf +1 x 2,700pF in parallel = 13.5nF = 13,500pF
C10-12/C22-24 = 4600pF =1 x 3600pF + 1 x 1000pF in parallel = 4600pF

Farnell UK part numbers
1000pF - Pt Nr. 126-4890 1.60 = 1.88 inc VAT (1-50)
2700pF - Pt Nr. 126-4899 2.30 = 2.70 inc VAT (1-50)
3600pF - Pt Nr. 126-4900 2.66 = 3.13 inc VAT (1-50)
4700pF - Pt Nr. 126-4901 2.66 = 3.13 inc VAT (1-50)

For those of you that do not have access to someone like Farnell I would be prepared to do a bulk buy and distribute accordingly.
Cost would be Farnell price plus VAT plus postage. I would expect postage to be low ie 2.00/€3.00/$3.00 as these things do not weigh much. If interested please pm me.


I also think that Quanghao should be given a big vote of thanks for taking on this job especially as English is not his prime language, and he has had to understand our abbreviations and colloquialisms.

Well done.

John Caswell

Last edited by John Caswell; 16th September 2010 at 04:27 PM.
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Old 16th September 2010, 06:54 PM   #343
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I am very interested in receiving those caps. Do you have access to LCR's FSC caps also? They are hard to find here in the USA and expensive.
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Old 17th September 2010, 10:23 PM   #344
Jezza56 is offline Jezza56  Australia
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Hi John, was just wondering if there was any reason for you running the caps in parallel to make up the value, I am wondering if there is an advantage or are the single values hard to obtain.

Regards Jezza
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Old 18th September 2010, 12:15 AM   #345
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Default Phono/Regulator PCB

Hi Jezza,
Well yes 4600pF is not a standard E** value whereas 4700pF is a standard value so 4600pF is not made, similarly 13n5F (13,500pF) is also not a standard value so it is relatively easy to make them up using standard values from the E12/E24 ranges.
These ranges have been devised such that say 4K7 +10% will be within the 5K6 - 10% limits therefore any resistor made to +/- 10% tolerance has to fall in either the lower limit of the next value higher or the upper limit of the next lower value. These rules apply to all of the E** ranges only the tolerance varies therefore the number of Rs or Cs in the ranges increases as the tolerance decreases hence +/- 1.0% resistors/capacitors come in E96 range, ie 96 vstandard values
However in practice resistors follow, say, the E96 range values but capacitors rarely exist outside the E12 series ie 1.0, 1.2,1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 and back to 1.0 but a decade higher.

John Caswell
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Old 19th September 2010, 07:38 AM   #346
Jezza56 is offline Jezza56  Australia
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Hi John,
Thankyou for taking the time to explain I now have a better understanding, I sourced my parts out of Holland from a great guy who is also very helpful, macmat.com they have lots of good gear.

Regards Jezza
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Old 20th September 2010, 10:47 PM   #347
Jezza56 is offline Jezza56  Australia
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Hi, Just wondering if there are any members in the Adelaide, Australia area, I may need some guidance when my Parts arrive, if there are any Good Samaritans out there it would be appreciated

Regards Jezza
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Old 22nd October 2010, 09:49 AM   #348
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I have designed an enclosure for this preamp.

I will post more pictures of assembly when I get the metal back net week

This will house both pc boards and an alps slider potentiometer.

The open sides will be closed with wood.
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Old 25th October 2010, 01:26 PM   #349
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Quote:
Originally Posted by tangmonster View Post
I have designed an enclosure for this preamp.

I will post more pictures of assembly when I get the metal back net week

This will house both pc boards and an alps slider potentiometer.

The open sides will be closed with wood.
IT IS VERY NICE
THANKS
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Old 25th October 2010, 01:43 PM   #350
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Quote:
Originally Posted by John Caswell View Post
Hi Jezza,
Well yes 4600pF is not a standard E** value whereas 4700pF is a standard value so 4600pF is not made, similarly 13n5F (13,500pF) is also not a standard value so it is relatively easy to make them up using standard values from the E12/E24 ranges.
These ranges have been devised such that say 4K7 +10% will be within the 5K6 - 10% limits therefore any resistor made to +/- 10% tolerance has to fall in either the lower limit of the next value higher or the upper limit of the next lower value. These rules apply to all of the E** ranges only the tolerance varies therefore the number of Rs or Cs in the ranges increases as the tolerance decreases hence +/- 1.0% resistors/capacitors come in E96 range, ie 96 vstandard values
However in practice resistors follow, say, the E96 range values but capacitors rarely exist outside the E12 series ie 1.0, 1.2,1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 and back to 1.0 but a decade higher.

John Caswell
Thank you for understanding my language problem!

PM: You have received the PCB's I sent?
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