Comparacion entre el SR71 y el SR71A

[mrarroyo]

Ray Samuel a creado un gran numero de amplificadores portatiles. Siendo sus dos ultimos el SR71A y el P51, el segundo estar siendo enviado antes del fin del ano. Desde que escuche el SR71 pense que era uno de los mejores amplificadores portatiles y uno que uso como referencia.

Desgraciadamente en Septiembre del 2007 lo vendi en Head Fi. Sin embargo esa persona lo puso a venta hace un par de semanas y yo se lo compre. Ironicamente pague lo mismo que el me pago, por lo que el salio muy bien en la compra venta. 

Hace poco Ray comenzo a vender el SR71A el cual ordene y en el que he puesto 725+ horas de rodaje (creo que le falta unas 250 horas adicionales ...  ) Hoy decidi comparar los dos y a continuacion incluyo el escrito que pondre en Head Fi. Desgraciadamente es en ingles. 

Ray Samuel's SR71 versus SR71A

For this comparison I used the following gear:
o   Apple iPod Classic 160 Gb
o   Apple Lossless Files
o   ALO Six Shooter line out
o   SR71 w/ "lots of hours"
o   SR71A w/ about 725 hours of burn-in
o   Yuin OK1 buds

For music I used:
o   Paul Hardcastle – Jazzmasters V
o   Keiko Matsui – Full Moon and The Shrine

First off I will say that I am a Ray's fan-boy, there up-front so no one has any doubts. To me it is easy to appreciate Ray's work. His gear is built like tanks, excellent customer service and ships amps faster than fast.

In the beginning and for the first 200 or so hours of burn-in I was not very happy w/ the SR71A. The bass was sloppy and way too much, to the point that it masked the upper mids and the treble. If I had not had experience w/ other of Ray's portable amps I would have sold it. However I remembered that both the Hornet "M" and the Tomahawk needed extensive burn-in (about 800+ hours) so I kept burning-in the SR71A, which as of today it has about 725 hours. I will probably keep burning it till it reaches 1,000 hours of burn in and post an update to this review.

I really wish there was a way to accelerate the process since we are looking at 30 to 40 days of continuous use to achieve 720 or 950 hours of burn-in. Many will not be able to devote said time specially if the SR71A is the only amp they own.

But those who have the time will be rewarded w/ an amp that drastically changes from 200 hours to 700+ hours of burn-in. It literally is like two different amps. Those who do not believe in burn-in, well I guess you are lucky and can enjoy or not from day one.

I would like to make sure to note that IMO the evolution of the SR71A is not subtle. You will notice that:
o   The bass stops being boomy and tightens up
o   The bass settles down to although punchy and powerful does not adversely affect the upper mids or the treble
o   The up-front personality of the SR71A mellows, and although it retains some of its "in your face" presentation it is not harsh nor obtrusive

I am lucky in being able to make this comparison. The SR71 used is the same one I sold over a year ago to a fellow head-fier. Luckily for me he put it up for sale a couple of weeks ago and I grabbed it. The seller sent it to Ray to have the gain adjusted from 2 (he used the SR71 w/ iems) to "normal" (gain of 6).

The two amps are close, yet each has enough differences that I would consider them to be different and to be used w/ different intent. The original SR71 is:
o   More relaxed and slightly mellower presentation
o   I find that its soundstage is a bit wider
o   There is more air between the notes, possibly because it is more extended in the upper mids and treble (minor but discernible)

On the other hand the SR71A has:
o   Deeper and punchier bass
o   More in your face presentation
o   Cuts through and demands attention

So if I was going on a trip (airplane, bus, etc.) or if I was going to be in place w/ a lot of things going on around me I would take the SR71A. Its attention grabbing and a more in your face presentation would allow me to tune the outside world and enjoy the music.

On the other hand if I was sitting down w/ a cup of coffee to read the newspaper, or if I was going to be studying at a library I would choose the SR71.

Since I believe in burn-in I will continue to burn in this amp. I will also be ordering a pair of Tysonic 9Volt batteries as recommended by Jamato8 to try. Will keep you posted.

[rodaballo]

Muchas gracias!!!

Que similitudes y diferencias tiene con el Minibox e+?

Saludos

[Torpedo]

Gracias por los comentarios Miguel. Tengo el SR-71 y me parece un muy buen ampli portátil. No le doy uso apenas, pero he podido probarlo con cosas muy exigentes y el aparato se desenvuelve con soltura y un tipo de sonido muy agradable, llámalo musical, natural o como prefieras. No tengo quejas en cuanto a su extensión o control de grave.

Del nuevo me gusta que sea algo más reducido y que el panel frontal esté cortado a nivel del resto de la caja. El reborde del SR-71 me parece muy poco práctico para llevarlo encima y usarlo con un iPod. Si tiene un sonido más "frontal" creo que me va a gustar menos  :

[mrarroyo]

Muchas gracias!!!

Que similitudes y diferencias tiene con el Minibox e+?

Saludos

En tres situaciones diferentes he comparado el MiniBox-E+ con el SR71A, usando una variedad de auriculares. Ejemplo:

- SuperFi 3 Live
- Yuin PK1
- Yuin OK1
- Senn PX100
- Ultrasone PROline 2500

En dichas ocasiones le pedi a mi esposa y a mi sobrino que escucharan y me dieran su opinion. Todos estamos de acuerdo el ... es superior. Te pido me des hasta que el SR71A tenga mas de 950 horas de rodaje antes de contestarte esa pregunta.

Lo bueno de esperar es que podre incluir la ultima version del Reference. Este fue modificado hace solo 3 semanas despues de intercambios que tuve con el Dr. Xin. Ahora el Reference tiene +/-325 horas de rodaje. En un par de semanas tendra 700 horas lo cual esta cerca de las 800 horas que en mi opinion le toma al capacitador de 22,000 uF que tiene el Reference.

Tambien incluire el iBasso D3, de este puedo decir que es una super ganga. Lo venden por $219 y en mi opinion suena mejor que el Pico o el Predator. Ambos cuest 2.5 veces mas.

Favor de darse cuenta que hay tantas opiniones como hombligos! 

[puvaen]

Hola mrarroyo;

¿Me puedes decir si el DAC del iBasso D3 sólo funciona con el USB o también funciona con la entrada "Input"?
¿La salida "Line out" dónde está, en la parte posterior donde pone "Link"?

Mi idea es conectar el iBasso con un "discman" ¿crees que esto funcionaría?

Muchas gracias por tus respuestas.

Saludos.

[mrarroyo]

Hola puvaen, si miras la foto del D3 notaras dos conneciones de 1/8" en el frente (a la izquierda del volumen). Uno es para alimentar el auricular y el del medio tiene dos funciones:

1) Entrada analoga de un cdp, iPod, etc.
2) Salida analoga del DAC que es alimentado via USB.

Si, tu idea de usar la salida de un "discman" para alimentar el D3 funcionaria bien. Lo mejor seria si el "discman" tiene un "line out" en vez de la salida del auricular del "discman".

[puvaen]

tu idea de usar la salida de un "discman" para alimentar el D3 funcionaria bien. Lo mejor seria si el "discman" tiene un "line out" en vez de la salida del auricular del "discman".

Efectivamente, mi CD-P tiene "line out", ahora hace falta que esa salida sea "real", que últimamente estoy muy escéptico 

Muchas gracias de nuevo mrarroyo.

[mrarroyo]

He leido en Head-Fi mucho sobre pilas que se descargan despacito. Segun los comentarios tambien tienen una baja resistencia.  Termine comprando varias y las estare usando en la comparacion est fin de semana. Las pilas son,

[mrarroyo]

November 8, 2008: Update

Today I spent a bit of time comparing them again. Now the SR71A has about 875 hours of burn-in. Furthermore I am using the Tysonic 200 mAh low discharge and low internal resistance 9 Volt rehargeable batteries. It is my opinion that the Tysonic batteries do make a slight difference in openness and in better extension. All four Tysonic batteries used were on their initial charge. Have no idea if they need burn-in or not, jamato8 will probably chime in and let us know.

For headphones I once again used the Ultrasone PROline 2500 and the Yuin OK1. For line out I used two by ALO: Six Shooter and SXC. The source used was as expected my 160 Gb iPod Classic w/ apple lossless files. For music I used Rachel Ferrel's album Rachel Ferrel. The song was "Waiting".



Below is a picture of the gear used today, and of the Tysonic batteries.





In a nutshell all of my findings from a week ago remain. The difference is that the amps are now much closer. At this rate by the time I reach 1,000 hours of burn in on the SR71A the only difference that may be left is an slightly deeper bass, a tad less extension, and a bit narrower soundstage. Or in other words the amps will be more alike than different.

An interst note is that w/ the full size cans both amps sounded better when I used the ALO Six Shooter. However when I switched to the Yuin OK1 then both amps sounded better w/ the ALO SXC. The differences were very noticable, to the point that IMO the Yuin OK1 sounded a bit "congested" with the ALO Six Shooter. This was very peculiar (dare I say weird?), as a norm the Six Shooter has shown to be the better of the two when you compare clarity, detail, and extension.

More to come at the 1,000 hour mark.