Author Topic: My DIY Hi-Fi Pre-Amp (Read 11759 times)

Tube Pro · « **on:** Sep 28, 2009 at 02:48 PM »

I'd like to thank first our tube gurus who inspired me and gave confident in making tube stuff.
Thanks for the valuable tips from Sir TonyT, Master J (JojoD818) and Edrel Sison.
As I've just started building the modified Dynaco MK3 amp, I decided to build a pre amp to match this.
http://www.pinoydvd.com/index.php?topic=100893.0

The Aluminium Chassis from China:

Tube Pro · « **Reply #1 on:** Sep 28, 2009 at 02:54 PM »

Chassis rough design: (with measurements)
12v - 0 - 12v @ 2.5-Ampere transformer will fit in this chassis. (for Filaments)
I'll use this tranny back to back with a lower wattage 24vAc to take its 110-v primary as HV B+.

Tube Pro · « **Reply #2 on:** Sep 28, 2009 at 02:58 PM »

Top Cover removed:

drilled rear panel for in/out RCA jacks and IEC power socket with fuse and switch.

Tube Pro · « **Reply #3 on:** Sep 28, 2009 at 03:05 PM »

with the 12AX7s

not yet done with drilling. I just used an available smaller drill bit and file to enlarge the holes.

gonna buy the appropriate 1cm drill bit later.

RCA jacks:

Tube Pro · « **Reply #4 on:** Sep 28, 2009 at 03:09 PM »

my 2nd Aluminium Chassis:
for another pre-amp with tone control circuit:

Tube Pro · « **Reply #5 on:** Sep 28, 2009 at 03:11 PM »

with the 12v / 2.5A power transformer and breadboard (not the actual circuit):

Tube Pro · « **Reply #6 on:** Sep 28, 2009 at 03:14 PM »

bottom (dimension):

inside:

Tube Pro · « **Reply #7 on:** Sep 28, 2009 at 03:32 PM »

Quote from: Tube Pro on Sep 28, 2009 at 02:54 PM

Chassis rough design: (with measurements)
12v - 0 - 12v @ 2.5-Ampere transformer will fit in this chassis. (for Filaments)
I'll use this tranny back to back with a lower wattage 24vAc to take its 110-v primary as HV B+.

the 12v-0-12v @ 2.5A and 24v @ 5va trannies:

the lower wattage 24v from China:

Trannies back to back:

JojoD818 · « **Reply #8 on:** Sep 28, 2009 at 04:07 PM »

Nice work, very clean metal work too sir.

Tube Pro · « **Reply #9 on:** Sep 28, 2009 at 04:42 PM »

Quote from: JojoD818 on Sep 28, 2009 at 04:07 PM

Nice work, very clean metal work too sir.

Thanks Master.

filing works courtesy by the low cost chinese file set.

top holes for the sockets, mejo napalaki kaya nilabas ko na lang ung mga sockets sa ibabaw, para d halata.

Thanks uli Master.
inspiration ko kc mga neat projects mo.

JojoD818 · « **Reply #10 on:** Sep 28, 2009 at 06:05 PM »

You should also ask Edrel for tranny tips and Tony for more circuit analysis. These guys are at the top of their fields, imo.

Tube Pro · « **Reply #11 on:** Sep 29, 2009 at 12:05 AM »

Quote from: JojoD818 on Sep 28, 2009 at 06:05 PM

You should also ask Edrel for tranny tips and Tony for more circuit analysis. These guys are at the top of their fields, imo.

I already have a pending Transformer order to Edrel Sison by the end of the year vacation leave. Those would be trannies for the modified Dynaco MK3 tube amp.

We're exchanging e-mails with the Russian guru, sir TonyT, about my ongoing 1st tube amp.
That's why you guys really contributed a lot for the (hope to be) success of these projects.

Thanks very much Masters.

John E. · « **Reply #12 on:** Sep 30, 2009 at 03:24 AM »

very impressive sir! congrats!

Tube Pro · « **Reply #13 on:** Sep 30, 2009 at 03:36 AM »

Quote from: JohnE. on Sep 30, 2009 at 03:24 AM

very impressive sir! congrats!

Thanks Sir JohnE.
I still don't have the final design. I have three choices, kaya mejo nagiging salawahan ako...

My primary concern is the power supply (probably two transformers back to back) that will fit inside with the circuit. It might be a point to point connection as the PCB will occupy add'l space.

Tube Pro · « **Reply #14 on:** Oct 03, 2009 at 12:52 AM »

update:
just drilled holes for the RCA in/out jacks..

joey · « **Reply #15 on:** Oct 03, 2009 at 09:51 AM »

Wow!

nice and clean! congrats po sir. truly inspirational!

san po nakakabili nito?

s2kov · « **Reply #16 on:** Oct 03, 2009 at 10:54 AM »

galing nyo sir, pulido!

oweidah · « **Reply #17 on:** Oct 03, 2009 at 11:53 AM »

congrats sir, ganda!!

Quote from: joey on Oct 03, 2009 at 09:51 AM

Wow! nice and clean! congrats po sir. truly inspirational!

san po nakakabili nito?

golden mars sales st./raon tapat ng deeco
734-8661 amy

joey · « **Reply #18 on:** Oct 03, 2009 at 11:54 AM »

Quote from: ojof00l on Oct 03, 2009 at 11:53 AM

congrats sir, ganda!!

golden mars sales st./raon tapat ng deeco
734-8661 amy

salamat repa! that

was quick!

edrel sison · « **Reply #19 on:** Oct 03, 2009 at 02:20 PM »

hi tube pro. for round holes you can get some hole saw of different sizes. I got mine from shenzhen and some from sam shui po. if only the plane ticket was further cheaper i want to have an overnight trip to HK and buy some parts...

http://www.holesaw.com.tw/e_product_main.htm

that is what hole saws look like.

Tube Pro · « **Reply #20 on:** Oct 03, 2009 at 06:35 PM »

Quote from: joey on Oct 03, 2009 at 09:51 AM

Wow! nice and clean! congrats po sir. truly inspirational!

san po nakakabili nito?

Thanks sir joey,
as per ojof00l, you can find these stuff in Raon (Quiapo) too. I got mine from Gongbei China 2 weeks ago. Thanks sir ojof00l for the info.

Luckily, we're just border away from the electronic giant so we can easily get those cheap stuff from there. Really cheap! Those gold plated 4 RCAs, 3 binding posts, 2 banana plugs, and a pair of banana plug extender just cost less than P400.
Can I know how much these accessories are being sold there in Raon so I can take some spare as we go back in China or HK next week/month?
Thanks again sir. I think you're about to DIY something, also Good Luck to your project.

Tube Pro · « **Reply #21 on:** Oct 03, 2009 at 06:45 PM »

Quote from: s2kov on Oct 03, 2009 at 10:54 AM

galing nyo sir, pulido!

Thanks sir s2kov,
D lang po masyadong halata ung errors, nakuha po sa pag kikil (file).

Tube Pro · « **Reply #22 on:** Oct 03, 2009 at 06:48 PM »

Quote from: ojof00l on Oct 03, 2009 at 11:53 AM

congrats sir, ganda!!

golden mars sales st./raon tapat ng deeco
734-8661 amy

Salamat sir ojof00l,
pki advise naman po kung magkano sa Raon ung mga gold plated jacks and plugs.
pwede akong magdala jan pag vacation ko.

Tube Pro · « **Reply #23 on:** Oct 03, 2009 at 07:08 PM »

Quote from: edrel sison on Oct 03, 2009 at 02:20 PM

hi tube pro. for round holes you can get some hole saw of different sizes. I got mine from shenzhen and some from sam shui po. if only the plane ticket was further cheaper i want to have an overnight trip to HK and buy some parts...

http://www.holesaw.com.tw/e_product_main.htm

that is what hole saws look like.

Hello sir edrel sison,

yes, i used that HSS hole saw for 2cm hole for the 12AX7 socket. I just didn't know how to call this thing kaya nahirapan akong bumili sa mga Chinese hardware d2 sa Macao. I printed it out then and showed to the salesperson, kaya ako nakabili. Thanks for the link, now I know what to call these boring tools.

I think I need to try that HSS hole cutter and the TCT hole cutter. Have you also tried those sir?
Mejo mahirap lang po sa hand drill kasi may tendency gumalaw kaya mejo luluwag ung clearance nya.

i dunno if you have a better technique other than using the drill press.
So you've got yours from Shenzhen China and Sam Sui Po HK. Dumadaan pa po ba kayo d2 sa Macao when you're having a tour? You can visit me here and we also have friends wherein you can stay overnight.
Good Luck sa mga projects. Paki PM nalang po ung quotation I mentioned in the Dynaco MK3 thread.
Salamat uli sir.

s2kov · « **Reply #24 on:** Oct 04, 2009 at 05:37 PM »

Hi edrel,

that's what i used for most of the project i diy'ed before but quite expensive. would you know how much is the price of common size for 8-pin, 9-pin and 4-pin tube socket?

Quote from: edrel sison on Oct 03, 2009 at 02:20 PM

hi tube pro. for round holes you can get some hole saw of different sizes. I got mine from shenzhen and some from sam shui po. if only the plane ticket was further cheaper i want to have an overnight trip to HK and buy some parts...

http://www.holesaw.com.tw/e_product_main.htm

that is what hole saws look like.

edrel sison · « **Reply #25 on:** Oct 07, 2009 at 12:00 PM »

andy mura lang yan sa china, in the range of between 200 to 400 pesos. sa manila the cheapest is tig 700 pesos. i think you can find some cheap alternatives in singapore.

joel this bore performs best using bench drills. if you are to use handhelds make sure the plate you are working on is properly clamped to a non moving base.

s2kov · « **Reply #26 on:** Oct 07, 2009 at 04:11 PM »

Hi edrel,

wala pa ko nakikita nyan d2 sa SG

Quote from: edrel sison on Oct 07, 2009 at 12:00 PM

andy mura lang yan sa china, in the range of between 200 to 400 pesos. sa manila the cheapest is tig 700 pesos. i think you can find some cheap alternatives in singapore.

joel this bore performs best using bench drills. if you are to use handhelds make sure the plate you are working on is properly clamped to a non moving base.

gob · « **Reply #27 on:** Oct 12, 2009 at 01:49 PM »

nice creation sir, congrats

Tube Pro · « **Reply #28 on:** Oct 13, 2009 at 05:33 PM »

Quote from: gobi on Oct 12, 2009 at 01:49 PM

nice creation sir, congrats

Salamat sir gobi,

To be continued pa po yan, at sobra kami busy sa work. Also, balak ko palitan ng 6SN7.
still finalising the circuit...

reynold · « **Reply #29 on:** Oct 13, 2009 at 09:24 PM »

Nag-umpisa na pala ang project mo, Nice and very neat

Another talent was born here in PinoyDVD, Congrats