First Watt M2 Power Amplifier by Nelson Pass

dhart86

Really sad to be selling this amp. It is a reference type amp by all accounts. It sounded fantastic in my rig, but I must sell to raise finances. My father passed away and I am in Florida to bury him. Apparently his insurance policy lapsed and as his only able child, I must bear the expense for his funeral.

I am not out for sympathy, Just wanted to explain why I am selling what I consider a prized piece. Fortunately I have a Joule Electra amp in house that I think will fill the void, (musically).

Below is a link to my ad, however my Polkie price is $1175 plus ship & paypal fee

http://www.usaudiomart.com/details/649339608-first-watt-m2-power-amp-by-nelson-pass

tonyb

Whats that I hear ? Brock knocking over small children to get to this ? lol

Sorry to hear about your pops bro, good luck with the sale and finances. Family first...

heiney9

Nah, it is on my list to try. But I have another Pass piece in the wings.

Sorry you have to let it go.

H9

lightman1

heiney9 wrote: »

Nah, it is on my list to try. But I have another Pass piece in the wings.

Sorry you have to let it go.

H9

So that's a pass on the Pass? Good thing too. What given his rep as no wire-twisting hack.



My condolences to you and your family @dhart. Good luck with the sale.

mrbiron

Hmmmmmm..................

lightman1

mrbiron wrote: »

Hmmmmmm..................

Dooooooo eeeeeeeeet, Freeeeeeeed.........

Unknown

This content has been removed.

WagnerRC

Sorry for your loss Darren.

mrbiron

lightman1 wrote: »

mrbiron wrote: »

Hmmmmmm..................

Dooooooo eeeeeeeeet, Freeeeeeeed.........

There are lovely reviews of people using First Watt with Zu speakers. When I talked with Sean prior to my purchase, that is what he was running. Might be a hard sell with the wife and the deal is, I have to let go of another piece of gear when bringing new in.

dhart86

Guys.....thank you
Losing my dad is very tuff, but I appreciate all the love i feel on the forum. You guys are like brothers.

Over the years, the acts of kindness I have received here are unrivaled.
Bob (Wagner RC) thanks for your willingness to help.
Dhaval (Jumpingdick) you recent offer has blown me away!
Thanks again for the condolences

kharp1

My condolences. Lost my mom 18 months ago and miss her every day.

steveinaz

Prayers for your Dad buddy. Good for you taking care of him.

kharp1

If I hadn't been on a shopping spree lately I'd be all over this one. May still...interesting piece I'd like to have in my system for a bit.

kharp1

Equal to the Aleph? Better, worse, about the same? Anyone?

ZLTFUL

At least equal, IMHO. The Aleph has a bit more aesthetic personality but the guts/concept is very similar.

heiney9

Different than the Aleph. This uses out put transformers. Conceptually similar to the Aleph, but an entirely different type of topology. Get your read on, 6 Moons has several in depth articles

kharp1

I've read a few articles on it, however, what I don't have is someones opinion from this forum that might have owned both who's opinion and equipment I might be familiar with.

heiney9

I hear ya, I'm just going on reviews and Nelson's comments. Such limited runs of both amps, going to be hard to find someone that has had both at the same time. The thing with FW and Pass, it holds its value so flipping if it doesn't mate well is not a concern.

Just my .02c. Love to see this stay here as it is an amp I want to try one day. But I have my sights set on another Pass piece at the moment.

H9

mrbiron

Me'sa tinks she be gone....

http://www.audioasylumtrader.com/ca/listing/Amplifier-SS/First-Watt/M2/Power-amplifier-by-Nelson-Pass/167853

ZLTFUL

heiney9 wrote: »

Different than the Aleph. This uses out put transformers. Conceptually similar to the Aleph, but an entirely different type of topology. Get your read on, 6 Moons has several in depth articles

Both are single stage class A designs.
Both are Mosfet output stages (although the First Watt adds Jfets into the mix)

In a general sense, they are very similar topologies with the differences being minor in the grand scheme of things.
Of course, we should differentiate if we are comparing the Aleph 3 or the Aleph 30 because in the case of the Aleph 3, there are considerable differences in topology. But the Aleph 30 improved a lot on the 3 and moved to newer technologies that were available at the time.

ZLTFUL

First Watt M2:


Aleph 30:


Aleph 3:

heiney9

ZLTFUL wrote: »

heiney9 wrote: »

Different than the Aleph. This uses out put transformers. Conceptually similar to the Aleph, but an entirely different type of topology. Get your read on, 6 Moons has several in depth articles

Both are single stage class A designs.
Both are Mosfet output stages (although the First Watt adds Jfets into the mix)

In a general sense, they are very similar topologies with the differences being minor in the grand scheme of things.
Of course, we should differentiate if we are comparing the Aleph 3 or the Aleph 30 because in the case of the Aleph 3, there are considerable differences in topology. But the Aleph 30 improved a lot on the 3 and moved to newer technologies that were available at the time.

The Aleph 30 doesn't have "newer" technologies compared to the Aleph 3. It has a bigger tranny, more output transistors and more filter capacitance. The output trannys are the same but on the Aleph 30 they are hand matched IN the circuit.


They are different as different can be the M2 uses a pair of Jensen output transformers and the M2 has zero negative feedback.

First Watt amplifiers are different than the aleph 3 and 30 lines. They have the same DNA so to speak, but the design parameters are completely different. Every NP amp sounds a bit different and you still need to mate them for synergy. You can't just replace one for the other in the same system and get the same synergy.

That said the M2 is one of the First Watt amps that is able to reasonably drive a "traditional" set of speakers (because it's voltage source vs. current source like most FW amps). Most of the First Watt amps are designed to single driver or simple crossover speakers.

H9

heiney9

Also the 2nd pic is NOT and Aleph 30; it's the Aleph J.

You got a lot of things mixed up

This is the Aleph 30



H9

heiney9

Also there are TWO amplification stages, not ONE. NP's DIY Zen line of amps were single stage.

They are single ended class A circuits.

Also J-fets are used at the input stage for the Aleph J, Mosfets at the output stage on the Aleph 3, 30 and J and M2

[Deleted User]

Fight!

I thought I was going to read how happy someone was.

pitdogg2

So sorry to hear about your dad Darren. Good luck with all that you have going on

heiney9

No fight, just setting the record straight and just realized this is FS thread not a general thread. Atleast it's on topic, sorry for that.

H9

heiney9

M2 Power Amplifier

The First Watt M2 is a two channel audio power amplifier delivering 25 watts per channel. It uses JFET and MOSFET transistors operating in Class A mode without negative feedback so as to produce a more musically life-like sound.

Negative feedback is a technique in which the input gain stage of an amplifier compares the input musical signal with the output of the amplifier and outputs a signal to the remainder of the amplifier which incorporates the original music mixed with corrections to reduce the errors made by the rest of the amplifier.

If an amplifier has high distortion, then negative feedback is very helpful in cleaning up the output going to the loudspeaker. Nevertheless many audiophiles view it as a necessary evil, affecting the musical quality of the sound since it involves mixing output errors and re-amplifying them. Excessive use of negative feedback creates issues with stability and although it improves the measured performance, is often associated with “sterile” sound character, and “subtracted” musical detail.

The M2 is a simple circuit whose output stage consists of a pair of complementary power Mosfet followers biased into pure Class A mode. These devices are the current gain stage of the amplifier, very linearly following the musical signal produced by the voltage gain stage. The voltage amplification is created through an auto-former which magnetically multiplies the input voltage.


Great attention has been paid to the linearity of the gain stages of the M2, resulting in a power amplifier whose performance is good enough to avoid negative feedback altogether. This is rarely achieved at a reasonable cost, and at this time the M2 serves as one of the best examples of the benefits of an amplifier with passive voltage amplification and no feedback.

The design is extremely reliable and will never need adjustment. It achieves a relaxed sound with a very organic character and dynamics well beyond the expectations of the power rating.

The simplicity and performance of the circuit allows a unique sonic experience that is likely to make you go through your entire record collection all over again.

heiney9

Aleph J

The Aleph J carries on in the tradition of the Pass Labs Aleph series, combining those elements that were particularly right about the Aleph 3 and 30, and re-thinking those areas open to improvement. Unlike its First Watt predecessors the F1 and F2, the Aleph J is a voltage source amplifier – a regular sort of amplifier like the ones you already know and love.

There are differences between the Aleph J and its predecessors:

1) Improved power supply filtration with about 20 dB less voltage ripple

2) Reduced gain on the active current source, giving better overall performance into 8-16 ohm loads

3) Input stage using high quality matched JFETs

4) Much higher input impedance and vanishing capacitance

5) 15 dB less negative feedback.

6) Even greater stability, operating without lag compensation

7) 15 dB less noise

8) No electrolytic capacitor in the signal path

Some things have remained the same – the Aleph J has the same basic 2-stage topology and uses output MOSFETs operating in single-ended Class A mode. It’s distortion character is still 2nd harmonic, and it’s sound is still natural and liquid. It is still very reliable. I don’t know of a load that can damage it.

heiney9

Reading the manual will give great insights to the M2 design

http://www.firstwatt.com/pdf/prod_m2_man.pdf

heiney9

Might as well throw in the entire sink.....

In regards to the M2 from the owners manual"


The input impedance is 100 Kohms, and the input capacitance is very low - only a few picofarads, so you will find it easy to drive it with single-ended tube equipment if you like.

The M2 has enough damping factor at 20 to work well with loudspeakers that mate well with tube amplifiers in general, and it delivers good performance into 4 ohms also – see the distortion curves. It is designed around relatively high efficiency speakers and it particularly shines with those that have 90 dB/watt sensitivity or greater, but you can hook it up to anything you like, as long as you adjust your expectations as to how loud it will play.

The amplifier requires about 1 hour of operation to reach normal operating temperature, and this warm-up time is appropriate for the most critical listening, but is not otherwise an issue. The amplifier’s final adjustments were been made after an hour, but the performance difference between 1 minute and 60 minutes is not very great.

I do not personally see a reason to run the amplifier all the time, but you can do that if you want to. The power supply capacitors are likely to last about 15 years or so, and while they will slowly dry out just sitting there, they will have a shorter life span with the amplifier running constantly. Also, at 200 watts it makes economic sense to shut the amplifier off if you aren’t planning on using it for the rest of the day.
Again, the heat sinks on this amplifier run fairly hot, and you want to make sure that they get adequate ventilation. They will run at around 25 degrees C. above the ambient temperature, which puts them around 50 degrees in the average listening room. At this temperature you should be able to put your hand on them for about 5 to 10 seconds or so.

The amplifier is capable of driving speakers which dip below 4 ohms as there are no limiters in the circuit. When the choice had to be made between sound and reliability into low impedance loads, I chose sound. For this reason please take care not to operate the amplifier into a short circuit or loads generally rated below 4 ohms.