Group Buy: Mauro Penasa MyRef Rev C kit

[Hiten]

I revisited Mauro's myref pages, yes first step would be to increase the value of caps as mentioned by linuxguru, sorry.

So bass should be good. Its not lacking, but the definition is weak/poor.

By definition you mean distinct separation of low fqs. right ??? Are you planning to audition this amp with different speakers ???
Thanks

 

[quad]

Like they say -

 

[quad]

Here's a nice toroid suitable for the MyRef, posted by
"Traveller" on diya -

Parts in Mumbai (India) - Page 13 - diyAudio

 

[borg]

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Got the transformer from a friend, ordered premium kit from linux guru for 7400(without pcb)
Now need to find a nice cabinet and other item like heatsink, connectors etc
Any pointers on where to get

 

[mymindinside]

Hi,
is this kit still available? i would be interested in a stereo set.
cheers,
mymindinside

 

[borg]

nearing completion , need to get the big caps and heatsink

 

[Hiten]

Looks neat. :thumbsup:
Thanks for sharing.

 

[gobble]

I am willing to let go of my soldered kit as my tube amp kit has arrived. However it has upgraded caps and costs twice the original unsoldered kit for the upgrades.

It was actually done up by linuxguru himself and I paid the extra for his labor and effort.

--G0bble

 

[linuxguru]

Folks, seriously consider taking Gobble's offer up - his board is a premium build with a total of 6 Rubycon Black Gates and 4 Nichicon Muse KZs across both boards, plus 4 Yamaha-branded Nippon Chemi-Con large PSU caps (no longer available). It comes with about 100-200 hours of burn-in, maybe more, on all the electrolytics, for free.

These boards sound great either with Fostex full-rangers or Sreekanth's two-way monitors - the darkness, imaging and soundstage are hard to beat.

 

[gobble]

Folks, seriously consider taking Gobble's offer up - his board is a premium build with a total of 6 Rubycon Black Gates and 4 Nichicon Muse KZs across both boards, plus 4 Yamaha-branded Nippon Chemi-Con large PSU caps (no longer available). It comes with about 100-200 hours of burn-in, maybe more, on all the electrolytics, for free.

These boards sound great either with Fostex full-rangers or Sreekanth's two-way monitors - the darkness, imaging and soundstage are hard to beat.

Uh Uh ... Into my 2nd day of listening and I want this for keeps!! Sorry guy's I rescind my offer. I had switched to 1.2 for last 3 months and only yesterday put the 1.3 back in its place.

There is something really special about the 1.3 and its only going to get better with more burn-in (currently around 100+ hours) ! :yahoo::clapping:

Even if I don't use it, its going to lie in my cupboard as a possible 2nd system.

The 1.2 by contrast is forgettable. The high freqs somehow sound lo-fi grainy gritty and there for namesake.

--G0bble

 

[linuxguru]

There is something really special about the 1.3 and its only going to get better with more burn-in (currently around 100+ hours) ! :yahoo::clapping:
...
The 1.2 by contrast is forgettable. The high freqs somehow sound lo-fi grainy gritty and there for namesake.

BTW, bcmbob@diyaudio, who has a configuration similar to yours, also loves his V1.3. AFAIK, the only differences on his V1.3 board are:

C13: Sonicap Gen I 1.5uF/160V
C6, C11: 47uF/16V Elna Cerafine
C9: 220uF/16V Black Gate STD

The V1.2 can be upgraded to sound better, but the constraint is limited physical space for some components, as compared to the V1.3 board. The main change I'd do on the V1.2 is to replace the Panasonic ECQ input coupling cap with an Arcotronics MKP 1uF/250V (which fits exactly). The Sonicap Gen I will also fit with some bending of leads, etc.

 

[gobble]

Well I got just the right amount of Bite in the brass instruments now and even the dynamics have improved. I have been yearning for this bite for last few years now and just on the even of assembling my tube kit, here comes the benchmark that I discover was lying with me in the cupboard all this while. It looks like taking extra time in wiring all the internal connectors tight and snug can reap great dividends. It is sounding astoundingly high-end. Then of course if the addition of my new Sub REL T5 adding to the bottom and lower mid harmonics to add more punch. It appears to have the effect of supporting the top end harmonics as well in terms of giving a tighter definition from top to bottom. :clapping:

Now I dont mind spending money on a proper casing/chassis and maybe even a DACT attenuator a year down the line - because I feel the kit deserves it!!

--G0bble

 

[borg]

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some more pics of the wip

 

[omishra]

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some more pics of the wip

Very nice. What is that small EI tranee for?

 

[borg]

there is a gamma2 dac sitting in front, the ei tfr is for the 5v lm317 based power supply(common pcb)

 

[omishra]

there is a gamma2 dac sitting in front, the ei tfr is for the 5v lm317 based power supply(common pcb)

To save that extra EI tranee, you can wind 25-30 turns of 24 or 25 SWG enameled copper wire on existing toroidal. Terminate with wires. wrap with cello tape. Which will free space and EMI from that small transformer.

 

[borg]

i had this one lying around, also totally isolated from the amp tfr

 

[borg]

i have completed wiring the myref premium kit (kit and pcb purchased from linuxguru).

powered by a toroid transformer 25-0-25v 6A. got this from a friend in china so only cost the duty (800rs)

the kit doesnot include the filter caps, Linux guru suggested i could get it from arihant bangalore, had a friend buy and courier it for me, 100rs/part for 4x 12000uF/63v nichicon

initially there was an issue with one chip getting hotter than other one. Fixed now. the chip was not making perfect contact with heatsink

I used the recently acquired gamma2 dac to drive the amp.There is no volume control as of now as i use the software player's control.

I use the setup in my signature to drive the dac. Ati 5850 hdmi- edge dvdo- optical- gamma 2 -myref= MS carnival 6 towers, speaker cable i made using cat 5 cable- all 8 wires shorted- 2 cablesper channel

used powerdvd 11 to play cd's and foobar 2000 for flac,( is it possible to pdvd play flac?)

i find it sounds better than foobar.

Initial impressions,there is no noise or hum and very silent between tracks. channel seperation is very good.Very good details.
I dont know the "audiophile terms" to describe sound. Treble is more pronounced,almost to the point of fatigue,
However i dont find a HUGE improvement over the onkyo 3300 in stereo mode, this could be the speakers. it is the weakest link in the chain. I plan to build a diy set for stereo listening, perhaps with scanspeak drivers.

Linux guru suggest i wait for 100 hours for the amp to be "burnt in" so hopefully it will improve

 

[linuxguru]

100rs/part for 4x 12000uF/63v nichicon
...
Treble is more pronounced,almost to the point of fatigue,
However i dont find a HUGE improvement over the onkyo 3300 in stereo mode, this could be the speakers. ...

Linux guru suggest i wait for 100 hours for the amp to be "burnt in" so hopefully it will improve

The Treble brightness will reduce over time as the electrolytics break in. You should see some of the edginess decrease as soon as 25 hours. (Also, are you sure that you got Nichicons and not Elna? Elna is what Arihant had in stock, and is the recommended choice).

The main component that can possibly be improved is the input coupling cap C13 - Sonicap Gen I 1.5uF/160V should be smoother, but at the cost of some micro-detail.

You can simply substitute a NatSemi LM318N opamp instead of the TI LM318P, and some of the treble brightness will decrease. Also check out my experimental LF01 hybrid/discrete opamp at diyAudio.com - prototypes are ready and undergoing evaluation as of now. The intent is to reduce some of the edginess from the LM318 opamp.

 

[borg]

thanks linuxguru for all the support
, i had forwarded my bangalore friend your email about the arihant and elna, but i got the nichicon

i will wait for it to be burnt in, to do the mods