[zeidoun]

Hi everyone,
I am interested in buying a new preamplifier for my 2 channels system and I am hesitating  between two options. The first option is to buy a used BP 25 (for around 1300 C dollars) and upgrade it to a BP DA (for an additional 1300 +taxes). The second option is to buy a 3-year old SP1 for 2800 dollars. I have read that the SP1 is equivalent to the BP25 in bypass mode. So, I assume that linking my cd player to the digital input of the SP1 (thus using the SP1 dac) and selecting the bypass mode would give me the same performance as the BP 25DA.
So my questions are:
1- Which one of these two options will result in the best sound quality?
2- Do a new BP 25DA and a 3-year old SP1 share exactely the same DAC?

Thank you very much for your help.
My equipment:
Amp: Bryston 3b st.
Mains: Paradigm Reference 60
Sub: Paradigm Servo 15
Cd player: Sony CDP 355 (300 cd charger with optical output)

[thomaspf]

This is a bit more complicated.

The SP1 uses older DACs and has less dyamic range and a higher noise floor than than the CS43122 plus discrete output stage used in the SP1.7 and the BP25-DA.

The BP25-DA has an external power supply which again results in a somewhat lower noise floor

The BP25-DA uses an asynchronous sample rate converter and implements a local oscillator that drives it's DACs independently of the incoming signal while the SP1.7 recovers it's clock from the input signal. This difference gives the BP25-DA higher jitter rejection and makes it more suitable for a wider reange of digital sources.

The BP25 in general has balanced inputs while the SP1.7 has not.

If you want to target 2-channels only this checklist should give you some guidance.

Cheers

   Thomas

[zeidoun]

Thank you Thomas,
I understand from your suggestion that, in theory, I will be better off with the BP25 DA. Did you make an AB comparison between the BP25 and the SP1?
Thanks.
Zied

[thomaspf]

Not so far the BP25-DA is pretty new.

However I can tell you about the difference between the SP1.5 and the SP1.7. The noise level in the SP1.5 was easily recognizable from my seating position while with the SP1.7 the ambient noise from my 9B-ST transformers dominate. I am still looking for a solution to that.

The impact of the asynchronous sample rate converter in the BP25-DA will depend on the quality of your digital source. I am using a computer and ended up buying a separate dejittering unit since sound cards do not deliver very high quality digital signals and the SP1.7 does not provide a dejittering stage. At this point I am very pleased with the sound from the SP1.7 which easily beats the DACs in my Rega Planet not to mention the analog outputs from the sound card.

James probably has done extensive comparisons and might help you with that.

Cheers

    Thomas