DIY Audio Projects Forum
http://diyaudioprojects.com/Forum/

4S Preamp - Can anyone provide a BOM
http://diyaudioprojects.com/Forum/viewtopic.php?f=9&t=6434
Page 1 of 3

Author:  eldarvanyar [ 07 Jan 2019, 09:45 ]
Post subject:  4S Preamp - Can anyone provide a BOM

Hi guys,

I like the look of the 4S Preamp and would like to give it a go.

I would like to try our some different 12AU7 valves with it.

Can anyone provide a BOM please for the UK?

Also, I am thinking of a painted Hammond Box for this amp, would they be big enough and which one or size would work best.

Thanks :D

Author:  Gab [ 07 Jan 2019, 16:50 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

I don’t have an actual BOM, but I can provide a parts list of my 4S with a cathode follower buffer. At least you’ll get an idea of what I bought to complete the project. Do you want to build the original 4S or the one with a cathode follower buffer ?

BTW, I used an aluminum 10x6x2" hammond enclosure. I don’t have a part number on hand, but you’ll find it easily on hammond’s website. Have a look to my build thread to see what it looks like !

Author:  Suncalc [ 07 Jan 2019, 21:20 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Here is a parts list for a complete 4S with the exception of the chassis. You will have to do the sourcing yourself as I buy everything from US suppliers. In this case, the internet is your friend.
Attachment:
4S Amplifier Parts List.numbers.pdf

As for the chassis; Go big! There is no virtue in working in overly small spaces and a large chassis (in general) means a quieter preamp.

Hope this helps.

Author:  eldarvanyar [ 08 Jan 2019, 18:16 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Thanks Matt I will take a look at the RS website

Author:  eldarvanyar [ 10 Jan 2019, 04:54 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Thanks Matt,
I would like to build this with good quality parts that will last a long time.
Can you please say where the main money on components should be spent for best return on investment for sound quality and performance?

Should I be looking at any boutique or exotic caps and resistors etc?

Are there any names, series or manufacturer in particular that I should look for!

For instance with the electrolytic caps - Nichicon, Panasonic etc seem to be good quality what range or series would you recommend?

Can you recommend a range of resistors, such as Holco, Vishay etc

Also can you please tell me what gauge wiring should I use if I follow the wiring guide for colour standards? Should it be high purity copper, silver plated copper etc

Many thanks

Author:  eldarvanyar [ 10 Jan 2019, 04:57 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Gab wrote:
I don’t have an actual BOM, but I can provide a parts list of my 4S with a cathode follower buffer. At least you’ll get an idea of what I bought to complete the project. Do you want to build the original 4S or the one with a cathode follower buffer ?

BTW, I used an aluminum 10x6x2" hammond enclosure. I don’t have a part number on hand, but you’ll find it easily on hammond’s website. Have a look to my build thread to see what it looks like !

Thanks Gab, I really appreciate your time. It would be great if you could attach a BOM for me and anyone else who would like to build this version.

Thanks again

Author:  Soundbrigade [ 10 Jan 2019, 14:44 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Many fancy ”audio grade” stuff is just standard stuff with golden printing AUDIO GRADE a higher price.
Also, many highly valued components (at extreme prices) are often inferior to standard components. Many capacitors on paper-base, introduce distortion, not common among plastic caps. But if you like distortion! Go for it.

If this is your first project, pick standard components that can withstand corrents/voltages/powers. Even if schematic says 1/2W resistors I go for 1W. And the general rule of thumb in electronic industry is to pick electrolytics with a rated voltage that is 10-15% higher than required.
Then, you can start fiddling and swap parts to find ”the sonic character” you like.

Author:  ILoveHiFi [ 10 Jan 2019, 15:07 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

I deffintly wouldn't aggree from my exprience that audio caps used in audio signal path (not power supply) is same as standard ones.
Amps love low distoriton caps like erse pulsex, any geniune metalised polypropene will also do very well and perfect for midend amps.
I typically find electyotic audio caps like fine gold to be good but not as good as metlaised polypropene.

I highly recomend audipo caps for input output and the bypass cathode, you can get them all for fair price on rs. Fine gold and ECWFE.
If you want the extra mile I would go erse pulsex, however I would say this is overkill for a schematic like this so the return is dimishing over standard metalised polypropene.
Also the geniune coax cable for input output as I find it has superiour sound quality over twisted which introduces noise.

As the amp is high voltage so low current you can do everything on very thinn gauge wire and even heaters just awg26 if you want to push it.
I recomend awg20-awg22 for heaters.
I'd say awg 22 would minize most resitance if your point to point wiering audio signal path and could improve sound quality.
AWG 24 is great for all audio path with low power and can hear sound improvement over awg26 but going lower than awg 22 tends to feel over kill and diminishing return

Author:  Soundbrigade [ 10 Jan 2019, 17:26 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

OT: A collegue of mine travelled to various producers in Japan and elsewhere in Asia and was frequently told that often, audio companies had the producers mark standard caps as Audio Grade in gold on a black or blue foil.
Worst was the electrolytics sold to car stereo makers. The prices could be up to 10 times the price for a standard cap in the ordinary metallic can - but the same content.

Author:  ILoveHiFi [ 10 Jan 2019, 17:38 ]
Post subject:  Re: 4S Preamp - Can anyone provide a BOM

Soundbrigade wrote:
OT: A collegue of mine travelled to various producers in Japan and elsewhere in Asia and was frequently told that often, audio companies had the producers mark standard caps as Audio Grade in gold on a black or blue foil.
Worst was the electrolytics sold to car stereo makers. The prices could be up to 10 times the price for a standard cap in the ordinary metallic can - but the same content.


Not sure about that one cause Fine Gold Geniune 100% from RS components has auditible diffrences from standard ones.

Page 1 of 3 All times are UTC - 6 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/