Author Topic: alexg's DIY Tube Projects (Read 63654 times)

alexg · « **on:** Mar 26, 2007 at 04:04 PM »

Update 03 November 2007:

Almost done drilling and cutting the alum top plate of my new tube amplifier:

When done, it will produce a GLORIOUS (hold your breath), 1.0 (ONE) watt of power per channel, hehehehe.....

It is a parafeed circuit, 12b4 tube providing the power and either a 5670 or 6n1p driver. It will be tube rectified using 6X5 rectifier and no electrolytic on the PSU!

------------------------------------------
Just finished this KT88 SE amp based on Mikael's design (diyaudio), with modifications done by arnoldc.

The power transformer and OPT was wound by Edrel Sison, the choke was a Hammond 193J. The driver is a Sovtek 6n1p and the power tubes are 6550/KT88. Rectifier is a 5u4-gb. It put out around 12 watts per channel.

The hefty power transformer:

My preliminary layout:

The aluminum top plate with all the holes done and the narra plinth assembled:

With all the topside component installed (not wired yet):

Finished the wiring last week and when I powered it up it did not smoke nor explode!

The fun part is, it plays music. Great sound, even better than my commercial KT88 push pull amp. I also finished oiling the narra plinth (used tung oil for varnish). Will take better pictures next time and post it here.

Thanks to ArnoldC, s2kov, Edrel, and Tony for the patience, advise and technical answers to all my newbie tech questions!

I had so much fun doing the amp, that I just started a preamp project. The PSU of this preamp project will be tube rectified and tube regulated, using plate chokes instead of plate resistors for load. As I type this, the power supply transformer and choke is being wound.

s2kov · « **Reply #1 on:** Mar 27, 2007 at 10:20 AM »

congrats alex!

Superman · « **Reply #2 on:** Mar 27, 2007 at 06:21 PM »

congrats!

butchoy8701 · « **Reply #3 on:** Mar 27, 2007 at 11:24 PM »

Congrats Alex! where did you buy the parts?

dana · « **Reply #4 on:** Mar 28, 2007 at 08:53 AM »

Congrats Alex!
Tung oil finished diy narra plinth base,clear coated machine buffed aluminum base?...etc
Tube rolling naman cguro kasunod nyan?

Tsaka, a nice horny preamp to match it with?.....

oweidah · « **Reply #5 on:** Mar 28, 2007 at 09:35 AM »

CONGRATS!

sarap makinig ng pasyon dyan nex wk!!!

alexg · « **Reply #6 on:** Mar 28, 2007 at 03:20 PM »

Quote from: butchoy8701 on Mar 27, 2007 at 11:24 PM

Congrats Alex! where did you buy the parts?

The KT88 and 6550 tubes, I already have, spare for my KT88 push pull amp. The 6n1p tube and the Hammond choke I bought from ArnoldC. The power transformer and output transformer, Edrel Sison of Fetronic, wind for me, also got some teflon wires and capacitor from him.

The resistors and electrolytic caps I got from RS online, the PIO motor run capacitors I got from my office, the IEC plug salvaged from a PC PSU. The switches are also salvaged from different sources. The 1.5mm OFC solid wire used for the ground bus, I got from Ace Hardware. The aluminum chassis, I bought from Binondo (along T. Alonso St.). Other odds and ends, got from Deeco.

alexg · « **Reply #7 on:** Mar 28, 2007 at 03:23 PM »

Quote from: dana on Mar 28, 2007 at 08:53 AM

Congrats Alex!
Tung oil finished diy narra plinth base,clear coated machine buffed aluminum base?...etc
Tube rolling naman cguro kasunod nyan?
Tsaka, a nice horny preamp to match it with?.....

Parts for the horny preamp is almost complete, Edrel will be finished winding the irons tomorrow (unfortunately I can't go to Rosario to pick it up, until next week).

Picked up the aluminum plate, aluminum rod and angle bar today from Binondo, also got the rectifier and regulator tubes from our friendly "tube magnate."

How about your "horny" project, how is it going?

alexg · « **Reply #8 on:** Mar 28, 2007 at 04:20 PM »

Quote from: oweidah on Mar 28, 2007 at 09:35 AM

CONGRATS!

sarap makinig ng pasyon dyan nex wk!!!

Hehehehe.... With a pair of Svet 6550C, the vocals are quite excellent! Must be good for pasyon...

Thanks.

oweidah · « **Reply #9 on:** Mar 28, 2007 at 05:19 PM »

Quote from: alexg on Mar 28, 2007 at 04:20 PM

Hehehehe.... With a pair of Svet 6550C, the vocals are quite excellent! Must be good for pasyon...

Thanks.

para di ka ma-ear-fatigue sa pabasa, try sub mo 6n1p ng amperex 6dj8 - yung A-Frame or L-bracket or dimpled getter

tol swerte ni brod, napamanahan mo agad ng tube amp ah!

christineG · « **Reply #10 on:** Mar 28, 2007 at 11:12 PM »

Quote from: oweidah on Mar 28, 2007 at 05:19 PM

tol swerte ni brod, napamanahan mo agad ng tube amp ah!

Actually hindi naman pamana, I just gave him an offer he cannot refuse.

Gives pa!

As soon as I go to Diliman, I can try a 6dj8.

I FORGOT THAT I WAS USING MY WIFE'S LAPTOP AND SHE WAS LOGGED IN, SORRY -- ALEXG

oweidah · « **Reply #11 on:** Mar 29, 2007 at 08:22 AM »

Quote from: christineG on Mar 28, 2007 at 11:12 PM

Actually hindi naman pamana, I just gave him an offer he cannot refuse. Gives pa!

As soon as I go to Diliman, I can try a 6dj8.

I FORGOT THAT I WAS USING MY WIFE'S LAPTOP AND SHE WAS LOGGED IN, SORRY -- ALEXG

shades of marlon brando aka don vito corleone

pero yung "Gives pa!" ang matindi

coordinate mo baka pabakasyon naman sa LB yung mama.

markmlists · « **Reply #12 on:** Mar 29, 2007 at 10:28 PM »

Congratulations!

your chassis maker also made the wooden panels? Thanks!

alexg · « **Reply #13 on:** Mar 30, 2007 at 05:54 AM »

Quote from: markmlists on Mar 29, 2007 at 10:28 PM

Congratulations!

your chassis maker also made the wooden panels? Thanks!

Thanks.

I did all the chassis work (metal and wood) including the automotive clearcoat of the aluminum plate and the tung oil varnish on the wood plinth. It was fun doing all of it.

I just started a new project, a preamp will post pictures of it too.

edrel sison · « **Reply #14 on:** Apr 03, 2007 at 02:32 PM »

power transformer

plate chokes

enjoy!

alexg · « **Reply #15 on:** Apr 03, 2007 at 02:41 PM »

Quote from: edrel sison on Apr 03, 2007 at 02:32 PM

power transformer

plate chokes

enjoy!

Edrel,

Thanks for winding these babies!

Time to be "HORNY"... hehehehe....

edrel sison · « **Reply #16 on:** Apr 03, 2007 at 03:16 PM »

a nice chrome finish would be pretty for that 2 plate chokes. c'mon post that very nice preamp chassis of yours!

s2kov · « **Reply #17 on:** Apr 03, 2007 at 03:23 PM »

edrel,

ako na kaya magpost para kay alex!

edrel sison · « **Reply #18 on:** Apr 03, 2007 at 03:32 PM »

sige nga andy, simulan mo!

alexg · « **Reply #19 on:** Apr 04, 2007 at 05:42 PM »

This is the external PSU of my "Horny Preamp Project."

The PSU has a power transformer with 180-0-180 80ma, 6.3V 2A, 6.3V 2A and 5V 0.8A taps, and a smoothing choke and uses motor run capacitors. The HV will be rectified using a Raytheon 6X5 rectifier and the filament using bridge diodes. Am utilizing a 4 conductor locking connector and will use a 3 foot umbilical cord going to the preamp chasis.

At the preamp chassis, the HV will be regulated using an 0d3 VR to 150VDC. Plate will be choke loaded and cathode biased using LEDs (will take pictures as soon as I started construction of the preamp chasis).

The design of this preamp was originally done by Gary (http://www.the-planet.org/linestage.html), first done locally by Edrel Sison with modification from TonyT (plate choke, etc). I borrowed Edrel's preamp and I was totally impressed by it.

Some valuable advise was given to me by ArnoldC (external PSU and LED bias) and TonyT on the (external PSU and plate choke).

All my irons were wound and designed by Edrel Sison of Fetronic, EPZA, Rosario Cavite. He also provided me with other components for the projects. The irons he did for my KT88 project are excellent, the ptx is barely warm to the touch and the OPTs sounds great!

Thanks to these guys for their advice. Thanks to Gerry, Dana and s2kov too!

By the way, this external PSU can also power a 12b4 with plate chokes and a foreplay 3. So depending on my mood, I can have the sweet sounding 7193, or a very neutral 12b4 or a classic 12au7 sounding preamp (foreplay 3).

These preamp should be joining my KT88 soon!

oweidah · « **Reply #20 on:** Apr 04, 2007 at 08:59 PM »

Quote from: alexg on Apr 04, 2007 at 05:42 PM

This is the external PSU of my "Horny Preamp Project."

congrats again alexg! sakto sa easter yan.

sure smooth sounding ang horny preamp mo, alagang jergens!

alexg · « **Reply #21 on:** Apr 04, 2007 at 10:22 PM »

Quote from: oweidah on Apr 04, 2007 at 08:59 PM

congrats again alexg! sakto sa easter yan.

sure smooth sounding ang horny preamp mo, alagang jergens!

Oooopppps, nabisto ang secret ingredient ko.

s2kov · « **Reply #22 on:** Apr 05, 2007 at 07:07 AM »

woohoo!

cograts alex!

dana · « **Reply #23 on:** Apr 05, 2007 at 09:39 AM »

ayuz na ayuz yan, ah! chassis pa lang, ulam na...
congrats on another masterpiece in the making....

ATJr. · « **Reply #24 on:** Apr 05, 2007 at 10:00 AM »

Quote from: alexg on Apr 04, 2007 at 10:22 PM

Oooopppps, nabisto ang secret ingredient ko.

Good job alexg,

we have to let the cat out of the bag....edrel do make fine transformers, pang export ang quality, now we have a go to person for transfomers..

just as we have gerry to go to for tubes...

alexg · « **Reply #25 on:** Apr 05, 2007 at 12:06 PM »

The back "mini-skirt" of the PSU with all the electrical connections finished:

Next will be sanding the aluminum plates and legs and the narra skirts.

I am just waiting for my socket hole drill bit, arriving tomorrow pm from Singapore, courtesy of my brother-in-law.

After drilling the socket hole, then I will apply polyurethane automotive clear coat, bake it and then soldering time!

alexg · « **Reply #26 on:** Apr 05, 2007 at 04:27 PM »

Just finished fitting the chassis for the preamp and doing possible tube layout.

oweidah · « **Reply #27 on:** Apr 05, 2007 at 08:13 PM »

nice legs! iba tlaga pag kompletos rekados ultimo sahog siguro primera klase = mouthwatering fingerlickin good! CONGRATS!

alexg · « **Reply #28 on:** Apr 05, 2007 at 09:55 PM »

Quote from: oweidah on Apr 05, 2007 at 08:13 PM

nice legs! iba tlaga pag kompletos rekados ultimo sahog siguro primera klase = mouthwatering fingerlickin good! CONGRATS!

Thanks.

Those legs are not as good looking as the UP campus figures' legs during our time.

ATJr. · « **Reply #29 on:** Apr 06, 2007 at 03:09 AM »

alexg,

if you are mounting the chokes underneath the chasiss, make them at right angle with each other to minimize interaction, if atop the chassis, get them as far away as possible...