Another vote for a passive preamp being a potential approach that sounds fantastic @Mnemarks. I’m a day or so into the same Townshend Allegri Reference that Greg has — and it sounds gorgeous. No proper comparisons yet, just a big smile on my face
(The difference between the Allegri’s Apple remote and the dCS remote is hilarious, though — a mate suggested I reenact the opening scene from Star Wars with one chasing the other…)
A question (perhaps @PAR, @Anupc, @PaleRider or @Ermos?) — given that my power amps do their peak output at 1.1V input and the Allegri Reference is effectively at pass-through at full volume (129, or 0dB attenuation on the front display), how does the maths work for the table part-way down this page?
At what point would the Allegri be passing 1.1V through to the monoblocks? I run the Bartok at 6V and don’t want to sizzle anything.
I’ve not needed to crank it much, but it’s only a matter of time/wine…
Actually, perhaps I’m just being dim — if I’ve not driven myself out of the room with this system and an active preamp before it’s unlikely that I’ve been anywhere near 1.1V with ANY of the different configurations I’ve tried.
Does that make sense, or am I yet dimmer than I thought?!
I had a good listen late last night with the Bartok set to 6v and 0db and the Baby Ref set to just before 12am (15 out of 31 steps), getting up and adjusting it ocasionally as necessary. I have to say that this is the best I’ve yet heard my system sound, all the things others have described, it was fabulous. Tbh I don’t think I need to do any more comparisons, I’m keeping the Baby Ref and I’ve already sent an email to MFA asking if they’re able to retrofit the optional remote control. I’ve also asked their opinion on what effect this might have on SQ as I have to assume it must have some negative impact.
Thanks again for everyone’s input, this has been a bit of an eye opener for me in terms of getting settings matched correctly.
The difference between Bartok set to 6V [email protected] and 1.1V input to your power amp with no attenuation by the Allgegri (129 setting) is ~14.74 dB. So according to the table the Allegri volume control should be set somewhere between 99 and 100 to deliver circa 1.1V in that circumstance.
However, as I said Bartok will rarely pass 6V as that requires a level from the recording to also be at 0.0dBfs. That level can only be for maximum peaks in practice and the mean level of the recording will be way below that given a wide dynamic range e.g. well recorded orchestral music. Modern pop/rock will be much closer to 0.0dBfs as a mean level as it typically has a narrow dynamic range. Even a 16 bit recording is way, way more than sufficient to capture it .
Yes, you may never have been near 1.1V input in practice but that depends on how loud " loud" is to you. I remember the designer of the ATC SCA2 preamp visiting me many years ago. The ATC 50 actives I run have the tri-power amp section biased to run in class A for 80% of output. Looking at my typical volume setting on the pre-amp he remarked that I had probably never run the power amps outside of class A. If I had that would result in an SPL in excess of 100dB as a guesstimate. I would rather keep my hearing and neighbours.
The Allegri Reference is a microprocessor-controlled, passive, autotransformer volume control (AVC) pre-amplifier. There are 129 individual 0.5dB steps, which give very fine volume adjustment at all listening levels. This incredibly wide range can accommodate very high source levels and very high sensitivity power amplifiers.
Although the signal path is totally passive in the Allegri Reference, the electronics and display require 12V DC. A universal power supply is supplied, with the appropriate plug, to suit your country’s mains supply. Power and music signal are always separate. There is no direct connection between the power supply and the signal conductors or ground.
The table below illustrates the extremely wide volume setting possibilities:
Maximum signal level: 4V RMS 8Hz; 10V RMS 20Hz and up.
Impedance: At 0dB, input impedance is 20kohm. At -10dB (normal listening, volume setting at 109, see above) input impedance is 200kohm, for a power amplifier load with 20kohm input impedance.
Since the decibel is defined with respect to power, not amplitude, conversions of voltage ratios to decibels must square the amplitude, or use the factor of 20 instead of 10. To convert decibels to voltage, see the link below:
If you set your Allegri to -10dB, its voltage ratio loss output will be 0.316228. So, if you set your Bartók to 6V out, your Allegri at -10dB will output 0.316228 x 6V = 1.9 V to your power amp. With normally mixed source material this would not overload your power amp’s input sensitivity. But if you set your Allegri to -15dB (volume setting 99), its output voltage will not exceed 1V. So, if you keep your Allegri’s output setting between -10 and -15dB (between 99 and 109) you will be safe.
I demo’ed the Bespoke Audio preamp; I loved those folks and their dedication to their craft. But for me, I concluded the Townshend Allegri Reference was preferable.
My point was that comparing one product to another which costs multiples of the comparative product is not of assistance.
The MFA baby is 1500 gbp. Of course the price for any specific Bespoke Audio product is unique - they are bespoke! The cheapest I can now find from reviews is 9000 gbp ( the one I found earlier was 15000 gbp). OK only 6 times more expensive. A bit like someone buying a Network Bridge and advising that they should have bought a Rossini.
As a further example, why buy a Rossini when a Vivaldi stack is better? Without establishing the buyer’s budget first that too is unhelpful advice.
Hi Pete, the MFA Baby Ref V2 is actually £6200 new in the UK, but still a lot cheaper than the Bespoke Audio. MFA have just released a new full chassis preamp simply called Reference V2 at £7200, which Jonathan Billington is quite excited about - it will be interesting to hear initial reports on it in the near future.
It also sounds like there may be a new version of the Baby Ref soon which will have remote control as standard, and would solve my problems…
Thanks Mike. Interesting that there is a new version of the Ref ( the basic Baby is much less expensive if course). Will that new version with remote make it directly competitive with the Townshend Allegri Ref? But at £7200 without the remote I already suspect that it might turn out to be more costly.
Anyway , whatever, I am afraid that I won’t be in the market in 2020 .
Hi Pete, both the new Reference V2 (£7200, already launched) and the Baby Ref V3 (to be launched, I’m assuming similar price to current v2, around £6000) will have full remote control as standard, and I believe he’s implemented the remote control differently to the previous (optional) remote, to make it much more reliable.
But from what I’ve read your Townshend is superb so no need to get itchy!
Thanks Mike. Just for the record it isn’t me that has the Townshend Allegri+. it is PaleRider and all2ofme . I am interested in it but do not see my being in a position to investigate one further during 2021 so meanwhile will stick with my EAR Yoshino 868 PL ( running NOS Tungsram tubes).
While I’m on, just want to re-emphasise the improvement in my system, having turned the Bartok up to 0db and controlling volume on the preamp. I had assumed that I wouldn’t lose anything the way I had it before (controlling volume between -10 to -15db on Bartok and higher volume on preamp) but unless I’m imagining things, the improvement is significant. No way I’m selling the preamp now, planning to get it upgraded with remote in the the New Year, funds permitting…
Once again, thanks to everyone for their input and help.
Thanks Mike for the precision of the price. I tested the mfa classic v2 at home. It was a good preamp but the Bespoke is far better. Yes the price is higher, but whe I compare thé construction, quality build and finition, I can understand Bespoke is more expensive. But compared to my previous preamp, ar ref5se , it far less expensive…
Hope you continue to enjoy it Ben.
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