• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Cheap Sakura Hybrid Tube Amp Modification

monreq

Member
2008-03-16 9:49 pm
I finished my final tweak in Sakura Hybrid Tube Amp. I said final because, this is the best tweak I've ever heard. Every details from the music played from the cdp were unveiled from this simple but powerful modification. The ideas came from Mel and the guts of doing the experiment in Sakura was by myself. The You Tube video is just to give an idea on the improvement. However, the actual listening session is better sounding, of course.

Video Of Previous Tweaks:

YouTube - Sakura Hybrid Tube Amp and Harmony X77 Testing Part 2older video

YouTube - Sakura Hybrid Tube Amp (Choke modifications) with AN Super 8 part 2 previous video

Final Tweak Listening Tests Video:
YouTube - Sakura Hybrid Tube Amp (Final Tweak) Part 1

http://www.youtube.com/watch?v=gBGoe_pfMiU

YouTube - Sakura Hybrid Tube Amp Final Tweak Part 3

Thanks for viewing folks. :)

Note: The tweaks were supervise by rascal 101 of Pinoy DVD Philippines.
 

monreq

Member
2008-03-16 9:49 pm
sounds awful to me.....through my shitty pc speakers, a mic, and then youtube encoding.

Yeah right, that's why you should use better one (PC Speakers). I use only Bose Companion 2 computer speakers. Better to try to use a good quality headphone. Thanks for the comment. You Tube Video is not reliable on listening test but can give some idea how it sound. At least it doesn't sounds like tin can.:D
 

monreq

Member
2008-03-16 9:49 pm
What a cool thread. Would it be possible to make clips pre- and post- tweak of the same track, so we can compare the sound? What kind of mains cables are you using? Sounds a bit like Shunyata Python in the bass.

Thanks for the comment. Sorry, I can't no longer do the recording without the tweak. The cables I am using is D.I.Y magnet wire gauge 21 for the signal and gauge 18 for the ground. You can experiment which gauge you prefer. Yes, the overall frequencies were improved after the tweak. But the sound is better of course in actual listening session.:)
 

TonyTecson

diyAudio Moderator Emeritus
2003-05-29 2:57 am
Maybunga, Pasig City
I'm not going to go into the details but the tweaks were on improving the drive circuit of the transistor based power amp of the Sakura AV-200 hybrid amplifier. Essentially, it is a way to reduce the effects of Miller capacitance.


miller capacitance of which stage? this hybrid amp has got several stages....
 

TonyTecson

diyAudio Moderator Emeritus
2003-05-29 2:57 am
Maybunga, Pasig City
Anyone has the schematic of this amp?

i do not have the schematic of the SS power amp stage but i copied the tube schemes:

this is the tube rectifier supplying +-6volts dc:
IMG_0466.jpg


and this is the 6N2 cathode followers running on +-12 volts:
IMG_0468.jpg
 
I'm sure my eyes must be deceiving me, but that appears to be a PSU using 5Z4 rectifiers to produce 6V rails. It would be difficult to think of a sillier way to do this. It also appears to be a circuit using cathode followers running from a 12V rail. It would be difficult to think of a good reason for doing this. Unless, of course, power efficiency and sound quality were not aims of the 'designer', but pushing naive 'audiophile' buttons was the aim. In this it appears he has been hugely successful!
 

TonyTecson

diyAudio Moderator Emeritus
2003-05-29 2:57 am
Maybunga, Pasig City
oh yes, DF96, i have had to deal with lots of those, i pull out the two 5z4's
and with just two resistors enable operation without those tubes.....
worse, each half of the 6n2's were left floating, i have had units come to me
with tubes lit but no sound, replacing with say 6bq7/6dj8 restored operations....
paralleled unused sections to avoid future problems.....