Is there a pre-amplifier(control) on the horizon?

frank7036

New member
Hi Alan,
Are you designing a pre to add to the March family? If so, will it have an-inbuilt phono-stage for MM/MC and is there a “hoped for” release date?
Otherwise, do you currently have a preference for particular 3rd party pre-amps in use with your amplifiers?
Regards.
Frank
 
Can I put in a suggestion for a current gain input stage for MC? I have a Aqvox 2CI with this as an option which works really well with an Audio Technica MC. A DAC board would be great…
 
@Andrew - While I like the idea of a trans impedance (TI) phono, I have not used one, and they are a bit rare.
I almost got one, but in the end I switched to a different brand of dual input phono stage.

This might be better done as a daughter card with MM and… then MC or TI for the second side??
 
@Andrew - While I like the idea of a trans impedance (TI) phono, I have not used one, and they are a bit rare.
I almost got one, but in the end I switched to a different brand of dual input phono stage.

This might be better done as a daughter card with MM and… then MC or TI for the second side??
Trans impedance, that’s what I was racking my brain for! The AQVOX unit I have does mm, mc and mc-ti (only through the balanced inputs). I think it helps if the mc has low impedance. It’s great because the mc has similar output to other line level sources and a similar strong sound. A dac I’m looking at has a volume control and my modded turntable blew up so it’s a bit moot at the moment! Fantastic to see a great company in WA and wish I’d known you were there when I was visiting Albany.
 
I assume you are up in Perth?
I have not stumbled upon many similar minded people around here.

The TI phono stages seem like they are a bit nuanced, and I have generally had a bit better results with dedicated phono stage… not hugely better. One if usually better off with a balanced phono input, so maybe keep your AQVOX..

Which DAC are you using?
 
I’ve got a Nuprime ida16 class d integrated; lots of power for my Maggie’s, digital straight in off the iPad / iPhone (since the bluenode decided to be a pain), 1 analogue in for the turntable, until that broke… I’m not having a good run. I’m in Geraldton. I was looking at a Sonnet DAC and Pass Labs or Sanders amps (dreaming…) but the class D is so good and the thought of getting something made in WA even better.
 
Noice!
I didn’t think Maggys were a thing here.
A friend has been through lots of amps trying to ones that power his, and I have gotten 2 sets of his left over amps.
I am not sure a Pass would have enough grunt? You probably want the 400W version.

I have an RME and am new to digital, and just stream it in via the iPad… but the TV AVP/AVR apparently does Roon, so I can try that at some point.

The TT is getting a dose of TLC in the form of a new motor controller, bearing, and a new (used) tonearm and new cart.
It is 38 years old.

The whole AVR/AVP is new to me, and I picked up 5 used speakers and some cheap AIYAMA for those and some tactile transducers.
It is a 5.0 at the moment, and should end up 5.2.2 which is in a multipurpose TV and lounge room.
Subs, Hypex amps, and the wood and router and saws are patiently awaiting me.

I used to know a few people that worked just outside of Geraldton, and visited there once or twice.
I suspect that there are not a lot of people like minded there, but at least the hipsters are on the tables now. ;)
 
Can I put in a suggestion for a current gain input stage for MC? I have a Aqvox 2CI with this as an option which works really well with an Audio Technica MC. A DAC board would be great…
Hi @Andrew
The pre amps will have optional MM/MC cards available. TBH the cards are the last item on the development plan, so the topology of the MC hasnt been finalised. Transimpedance for MC does have some advantages. We shall see.....;)
 
I’ve got a Nuprime ida16 class d integrated; lots of power for my Maggie’s, digital straight in off the iPad / iPhone (since the bluenode decided to be a pain), 1 analogue in for the turntable, until that broke… I’m not having a good run. I’m in Geraldton. I was looking at a Sonnet DAC and Pass Labs or Sanders amps (dreaming…) but the class D is so good and the thought of getting something made in WA even better.
Hi @Andrew
You made the right decision going with class D, even if it wasnt one of ours :).

Looking at the Sanders I get concerned when I see quotes like "Roger's unique, 100% efficient, linear, regulated power supply". Its unique al right because no such thing exists! The Pass Labs are just daft money. :)

Which Maggies do you have?
 
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Noice!
I didn’t think Maggys were a thing here.
A friend has been through lots of amps trying to ones that power his, and I have gotten 2 sets of his left over amps.
I am not sure a Pass would have enough grunt? You probably want the 400W version.

I have an RME and am new to digital, and just stream it in via the iPad… but the TV AVP/AVR apparently does Roon, so I can try that at some point.

The TT is getting a dose of TLC in the form of a new motor controller, bearing, and a new (used) tonearm and new cart.
It is 38 years old.

The whole AVR/AVP is new to me, and I picked up 5 used speakers and some cheap AIYAMA for those and some tactile transducers.
It is a 5.0 at the moment, and should end up 5.2.2 which is in a multipurpose TV and lounge room.
Subs, Hypex amps, and the wood and router and saws are patiently awaiting me.

I used to know a few people that worked just outside of Geraldton, and visited there once or twice.
I suspect that there are not a lot of people like minded there, but at least the hipsters are on the tables now. ;)
Respect and admire your DIY! I got the Maggie’s, IDA amp and a bluesound 2i streamer from Mcleans audio in QLD, they were great to deal with. I put a heap of money and time into a technics 1210 hoping for something reliable, not too far from digital clean and clear but with some LP magic I remember as a kid and it worked well… apart from the reliable hic up! If I can’t fix I might go a Rega p3, though it might be more sensible to stick with digital for me. I think it’s great kids got into LP, keeps it going ha ha! its a bit of a desert in Geraldton for audio but I’m lucky to have a few friends with no interest in hi fi but good ears for music I can test my set up on.
 
Hi @Andrew
You made the right decision going with class D, even if it wasnt one of ours :).

Looking at the Sanders I get concerned when I see quotes like "Roger's unique, 100% efficient, linear, regulated power supply". Its unique al right because no such thing exists! The Pass Labs are just daft money. :)

Which Maggies do you have?
Hi Alan, great to hear from you, I’d love to buy something “local”… I’ve got 1.7i Maggie’s; the most I could manage in cost and size, 3.7 being 3x the cost and larger. I got the IDA 4 years ago, everything plugs into 1 unit, 400w into 4 ohm, volume around 50/100 for around 80 db @ 2.5m. The Maggie’s are 87db inefficient but a resistive load, dipping to 2 ohm in the high freq but haven’t caused any probs for the IDA so far. I read Sanders technical papers so I hope it’s not a complete story! Sanders are popular with Maggie owners but a $7k amp is now $11k and Pass are more like $25k at 400w into 4 ohm + the heat and idle power consumption. I shouldn’t worry too much about the power but it just seems dumb to use a KW for a lighted metre.
 
Hi Alan, great to hear from you, I’d love to buy something “local”… I’ve got 1.7i Maggie’s; the most I could manage in cost and size, 3.7 being 3x the cost and larger. I got the IDA 4 years ago, everything plugs into 1 unit, 400w into 4 ohm, volume around 50/100 for around 80 db @ 2.5m. The Maggie’s are 87db inefficient but a resistive load, dipping to 2 ohm in the high freq but haven’t caused any probs for the IDA so far. I read Sanders technical papers so I hope it’s not a complete story! Sanders are popular with Maggie owners but a $7k amp is now $11k and Pass are more like $25k at 400w into 4 ohm + the heat and idle power consumption. I shouldn’t worry too much about the power but it just seems dumb to use a KW for a lighted metre.
Hi @Andrew

There is a bit of a mythology that has developed regarding Maggie's that they are terribly difficult to drive. For most of the models this isn't the case. You obviously have done your research and understand the impedance plot of the 1.7.

Yes it does drop to 2 ohms at 20kHz, but there is very little music going on up there (maybe 50dB less than at 1kHz) so very little power is required. Hence its just not an issue. It's also primarily a resistive load, not that reactive loads are an issue for class d. They are a problem for class A or A/B.

The only issue for the Maggie's is that they are inefficient. The manufacturer specs are somewhat optimistic. So they do need a lot of power. Again not an issue with class d.
 
Thanks Alan! Just as well there isn’t a lot of music energy at 20khz as my partly damaged, old ears won’t be responding anyway! + the Maggie’s have some resistors in reducing the treble. I’m sure Magnepan are being a bit liberal with their 87db at 1 Watt at 1 metre and isn’t there a little voltage cheat about what 1 watt into 4 ohm is? My Nuprime has enough power, at 5/10, to get the Maggie’s to peak around 85db at 2.5m which is a good volume for me. I’m thinking an expensive DAC with an analogue volume control and your 501s might a big improvement or I might already be in diminishing return territory and better off sticking with the Newprime?
 
Thanks Alan! Just as well there isn’t a lot of music energy at 20khz as my partly damaged, old ears won’t be responding anyway! + the Maggie’s have some resistors in reducing the treble. I’m sure Magnepan are being a bit liberal with their 87db at 1 Watt at 1 metre and isn’t there a little voltage cheat about what 1 watt into 4 ohm is? My Nuprime has enough power, at 5/10, to get the Maggie’s to peak around 85db at 2.5m which is a good volume for me. I’m thinking an expensive DAC with an analogue volume control and your 501s might a big improvement or I might already be in diminishing return territory and better off sticking with the Newprime?

Hi @Andrew

Yes, not a cheat per se but there is confusion over efficiency and sensitvity. These are different things.

Sensitivity is the relevant piece of information. It is how loud the speaker plays for a given input voltage. This is normally taken as 2.83 volts rms. So speaker impedance which varies across the frequency range is not relevant.
When applied to a 8 ohm resistive load this represents 1 watt of power, but in a speaker it could be anything.

Efficiency is how much power the speaker converts into sound. This is usually tested at 1watt. However no speaker is actually 8 ohms across its frequency range. It's a bit meaningless TBH and of little use as a metric.

Another thing to be aware of is that no speaker has a flat frequency response. So if you use a sine wave at a specific frequency you can game the results by choosing a frequency that corresponds with the highest level.

So you need to test across a range of frequencies,say 500Hz to 2kHz with a white noise signal and rms it to give a more representative value.


The P501 is possibly overkill for the Maggie's, but would sound great. The P421 or P422 would possibly be more appropriate. They are much better technically than the Nuprime, so will sound better and drive the Maggie's better.

If you look at the nuprimes spec it's power output doesn't increase from 8 to 4 ohms which implies an inadequate power supply. It's thd + n figures show its much higher noise and distortion than the P421/p422/p501.

In terms of DACs use something like a Topping D90se driving the amps directly. It's performance is state of the art, but you could use the nuprime pre out to feed the P422. That would make a lot of sense as I suspect the dac section of the nuprime is relatively much better than its power amp section.
 
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