Topic: JojoD's Tube and Solid State Projects

[JojoD818]

Jo, tapos na ba yung sa akin? 

Yes sir, hindi ko lang nadadala kay Joey since hindi pa ako ulit nagpupunta sa kanya.

[eXg]

doc,

t-amp yan, it's a digital amp in a new case with outboard reg psu. 

 

Are Tripath chips available locally na ba?  just wondering kg pwede ng bumuo...

[JojoD818]

Are Tripath chips available locally na ba?  just wondering kg pwede ng bumuo...

afaik, hindi pa available locally.

besides, it would be a challenge to design a pcb for this, or even solder it. 



 

[eXg]

kg sa 'yo challenge, paano naman kaya kami mere mortal solder slinger 

[JojoD818]

kg sa 'yo challenge, paano naman kaya kami mere mortal solder slinger 

kayang kaya mo yan eXg, practice makes perfect.

for me, that's where I get my clean "rush" 

[JojoD818]

"Schumi"






 

[alexg]

"Schumi"






 

Gorgeous!

[docsialu]

Gorgeous!

ano naman to jo?

[JojoD818]

ano naman to jo?

doc,

tube preamp/linestage yan

[eXg]

the vibrant colors are eye-catching!!!

[bumblebee]

My 1500th post to JojoD

[JojoD818]

My 1500th post to JojoD

I don't know what to say.

Thanks man! 

[BuLLeT]

"Schumi"






 

Yo!

ganda naman ng kinalabasan. Ngayon ko lang nakita ah. Wowoweee... hats off to you Master Chief. Ang bilis naman ng pagkakagawa. Colorful.

Na test na ba Chief?

[JojoD818]

Na test na ba Chief?

Whoa!

tumutunog naman.   

 

seriously, proving grounds na lang. I still have time for fine tuning, yes?

[RU9]

tumutunog naman.   
seriously, proving grounds na lang. I still have time for fine tuning, yes?

Jo,

Anong basis ng design? Baka bagong approach.
Anong ang plus factor?

Louie

[JojoD818]

Jo,

Anong basis ng design? Baka bagong approach.
Anong ang plus factor?

Louie

Hi Louie,

Kamusta na?

It's a ccs'ed voltage amp with led cathode bias and a cathode follower. The new approach and plus factor is the style of wiring the tubes so the owner need not buy a pair, even a single tube can be used for rolling, or mix-match to suit individual performance tastes. Btw, it is also already using a NOS Sylvannia 5Y3GT so may not need to roll the rectifier (for me at least).

Best Regards

[Vhongbiker]

12AU7 Tube Preamp and Bi-T-Amp Project









sir pm mo naman ako how mugagastos ko dito.

thanks

[choariwap]

hi jojo,

finally got the amp settled, it sounds fantastic! i got used to the sound now, at first medyo masakit yung highs compared to the sennheisers i have, but now...magic



the DAC1 is sitting on my ghetto isolation mount: an extra 80mm PC case fan under and an old ratty mouse pad. cuts down vibration, dont hear any improvement sound wise though...

[JojoD818]

pm sent bro.

thanks 

hi jojo,

finally got the amp settled, it sounds fantastic! i got used to the sound now, at first medyo masakit yung highs compared to the sennheisers i have, but now...magic



the DAC1 is sitting on my ghetto isolation mount: an extra 80mm PC case fan under and an old ratty mouse pad. cuts down vibration, dont hear any improvement sound wise though...

I'm glad you liked that heavyweight! How's the heat dissipation?

 

[JojoD818]

Why do they call this browndog when  it's actually green?   

[JojoD818]

QSC USA850 pro audio power amp + tube preamp = party

 



Replaced: all 16 opt and 4 driver transistors.

[JojoD818]

Mundorf signal cap and psu upgrade...








 

[choariwap]

I'm glad you liked that heavyweight! How's the heat dissipation?

 

heat dissipation can be better, i have to point a fan at it or else it gets too hot to touch.
the dc offset on the right is fluctuating, at power on it's around 3mV, then after warm up it plays between at 26 - 35 mV. the left side is pretty constant at 15 - 18 mV at all times.

is there a way to reduce the right channel offset further? or wala na tayong piyesa ? nakakapraning kasi kung pumapatak na ng 30mV

[JojoD818]

heat dissipation can be better, i have to point a fan at it or else it gets too hot to touch.
the dc offset on the right is fluctuating, at power on it's around 3mV, then after warm up it plays between at 26 - 35 mV. the left side is pretty constant at 15 - 18 mV at all times.

is there a way to reduce the right channel offset further? or wala na tayong piyesa ? nakakapraning kasi kung pumapatak na ng 30mV

the fets that were used are the "best" match ones. I can try and redo a matching session with the remaining fets if you want.

don't worry, it's way below NP's recommendation of 50mV and the industry standard of 100mV. 

[ATJr.]

is there a way to reduce the right channel offset further? or wala na tayong piyesa  ? nakakapraning kasi kung pumapatak na ng 30mV

don't be...as long as the offset is below 100mV as jojo said, there is no cause for concern, besides, there are many other factors that make offset impossible to trim to 0volts, and  component matching is just one of them.

jojo, can you pm me the schematic for this?thanks

[JojoD818]

jojo, can you pm me the schematic for this?thanks

Hi Tony,

It's in pdf format. If this link doesn't work, I'll email it to you.

http://www.firstwatt.com/downloads/f1_srv_man.pdf#search=%22f1_srv_man%22

 

EDIT: Better yet, Google for this file...

- f1_srv_man.pdf -

 

[choariwap]

the fets that were used are the "best" match ones. I can try and redo a matching session with the remaining fets if you want.

don't worry, it's way below NP's recommendation of 50mV and the industry standard of 100mV. 

it seems to be stabilizing, i'll monitor over the next few weeks if it settles. thanks!

sir tony,
gawa ka rin?

[ATJr.]

sir tony,
gawa ka rin?

sana if only i have the time, and the desire, but for now ipon-ipon muna ng parts, tools and equipment, darating din tayo dyan...

jojo,
thanks for the link, mukhang nagsawa na ang industry sa pababaan ng distortion figures, mukhang nabaligtad na, pataasan naman ngayon,   5%distortion at 10watts? kung noong araw yan, baka walang bumile nyan.

the one thing going for this amp is simplicity, lack of global feedback means fast reacting amp, with no hangups....

[JojoD818]

sana if only i have the time, and the desire, but for now ipon-ipon muna ng parts, tools and equipment, darating din tayo dyan...

jojo,
thanks for the link, mukhang nagsawa na ang industry sa pababaan ng distortion figures, mukhang nabaligtad na, pataasan naman ngayon,   5%distortion at 10watts? kung noong araw yan, baka walang bumile nyan.

the one thing going for this amp is simplicity, lack of global feedback means fast reacting amp, with no hangups....

anytime. 

despite of that, I was surprised on how clean it sounded, and most of all - it was really an adventure building that amp. 

[JojoD818]