Post by strindl on Jul 23, 2009 23:51:25 GMT -5
It's been a few days now since I took delivery of a pair of XPA-1's and I' ve had enough of a chance to audition them to give my first impressions.
First of all, they are an impressive piece of work. I've been involved in high end audio for 30 years and these amps rank right up there in appearance and build quality with the best of them. I've owned multiple Nelson Pass era Threshold amps and currently still own 4 of them. The crown jewel in my Threshold collection is the SA/4e. This amp is a 97 pound pure class A amp rated for 100 watts per channel of pure class A power at 8 ohms. It puts out more power than that but switches to class AB above 100 watts at 8 ohm.
I've had it tested and it puts out 320 watts per channel continuous at 4 ohms, both channels driven. It is a dual mono design with a pair of 800VA toroidal transformers and 190,000 micro farads of filter capacitors. It uses 26 output transistors per channel. This amplifier was hand built in small numbers in California. I bought mine new in 1993 and paid $6,300.00 for it.
The XPA-1's by comparison each use a 1200 VA toroidal transformer and 130,000 mfd of filter capacitors with 24 output transistors per channel.
The speakers that I am driving with the SA/4e and the XPA-1's are a pair of Thiel 3.6's. They are a three way speaker weighing 107 pounds each with a heavily braced and constructed cabinet. They are nominally 4 ohms but their resistance does drop below 4 ohms in significant parts of the frequency spectrum. They have a -2db point of 28 hz. They also are a power hungry speaker with an 86 db sensitivity. A good test for a powerful set of Emotiva mono blocs.
I unpacked them and placed them each on a separate Velodyne F1500r subwoofer.. located in the left and right front corners of my listening room , slightly behind and to the sides of the Thiels. The subwoofers are the perfect size for the mono blocks. I hooked them to the balanced outputs of my preamp with 35 foot monoprice balanced XLR cables. I used 12 gauge Monoprice speaker cables..about 6 feet on each.
I plugged both XPA-1's into a separate 15 amp circuit. They are the only devices using it. The rest of my audio equipment , except the subwoofers, have their own 20 amp circuit. My video equipment and the room outlets and lights have another 20 amp circuit.
After the mono blocks were hooked up to the Thiels, I turned the equipment on and let things settle down for 10 minutes or so before beginning my listening.
I'm going to be blunt here and say right out, after a couple hours of listening that first night, I was not at all happy with the sound I was hearing. The highs were overly bright and harsh through the Thiels. Not at all the type of sound I was used to from them with the Threshold amp.
I decided to leave the XPA-1's powered up for 24 hours or so to give them a chance to break in a bit and try again the next night. I am very glad I did that and didn't dismiss them out of hand after my first experience with them.
My second night with the amps was a totally different experience. From the first note of The Nylons singing "Time of The Season" with their great vocals and harmonies along with the deep bass of the drums, I finally was able to hear what they were capable of. Deep powerful bass, effortless sound and superb imaging. These things just needed a 24 hour burn in to show me their stuff. I'll be spending the next couple weeks continuing to evaluate the XPA-1's . I'll switch back to the Threshold periodically to refresh my memory of the sound of that.
All in all, after three days I am now very happy with my investment in the XPA-1's. They did require that burn in first though.
Here is one of the amps in position on top of the Velodyne. There is a matching set on the other side of the room.
and here is the rest of the equipment:
First of all, they are an impressive piece of work. I've been involved in high end audio for 30 years and these amps rank right up there in appearance and build quality with the best of them. I've owned multiple Nelson Pass era Threshold amps and currently still own 4 of them. The crown jewel in my Threshold collection is the SA/4e. This amp is a 97 pound pure class A amp rated for 100 watts per channel of pure class A power at 8 ohms. It puts out more power than that but switches to class AB above 100 watts at 8 ohm.
I've had it tested and it puts out 320 watts per channel continuous at 4 ohms, both channels driven. It is a dual mono design with a pair of 800VA toroidal transformers and 190,000 micro farads of filter capacitors. It uses 26 output transistors per channel. This amplifier was hand built in small numbers in California. I bought mine new in 1993 and paid $6,300.00 for it.
The XPA-1's by comparison each use a 1200 VA toroidal transformer and 130,000 mfd of filter capacitors with 24 output transistors per channel.
The speakers that I am driving with the SA/4e and the XPA-1's are a pair of Thiel 3.6's. They are a three way speaker weighing 107 pounds each with a heavily braced and constructed cabinet. They are nominally 4 ohms but their resistance does drop below 4 ohms in significant parts of the frequency spectrum. They have a -2db point of 28 hz. They also are a power hungry speaker with an 86 db sensitivity. A good test for a powerful set of Emotiva mono blocs.
I unpacked them and placed them each on a separate Velodyne F1500r subwoofer.. located in the left and right front corners of my listening room , slightly behind and to the sides of the Thiels. The subwoofers are the perfect size for the mono blocks. I hooked them to the balanced outputs of my preamp with 35 foot monoprice balanced XLR cables. I used 12 gauge Monoprice speaker cables..about 6 feet on each.
I plugged both XPA-1's into a separate 15 amp circuit. They are the only devices using it. The rest of my audio equipment , except the subwoofers, have their own 20 amp circuit. My video equipment and the room outlets and lights have another 20 amp circuit.
After the mono blocks were hooked up to the Thiels, I turned the equipment on and let things settle down for 10 minutes or so before beginning my listening.
I'm going to be blunt here and say right out, after a couple hours of listening that first night, I was not at all happy with the sound I was hearing. The highs were overly bright and harsh through the Thiels. Not at all the type of sound I was used to from them with the Threshold amp.
I decided to leave the XPA-1's powered up for 24 hours or so to give them a chance to break in a bit and try again the next night. I am very glad I did that and didn't dismiss them out of hand after my first experience with them.
My second night with the amps was a totally different experience. From the first note of The Nylons singing "Time of The Season" with their great vocals and harmonies along with the deep bass of the drums, I finally was able to hear what they were capable of. Deep powerful bass, effortless sound and superb imaging. These things just needed a 24 hour burn in to show me their stuff. I'll be spending the next couple weeks continuing to evaluate the XPA-1's . I'll switch back to the Threshold periodically to refresh my memory of the sound of that.
All in all, after three days I am now very happy with my investment in the XPA-1's. They did require that burn in first though.
Here is one of the amps in position on top of the Velodyne. There is a matching set on the other side of the room.
and here is the rest of the equipment:
