Beresford Bushmaster DAC

[pumpkineater23]

How many watts into 8 ohm are we talking?

140 watts I believe. It's a Quad 606.

[northwest]

The lack of variable out on the Bushmaster is obviously not big issue for me as I use a separate active preamp (and I also use the DAC as a headphone amp), but I'll still be interested in buying the add on variable output and remote volume option in the future as I like having extra options to try (and like changes in my preamp scenario from time to time). If the Bushmaster variable output is similar to the Caiman variable out (which sounds very good) I'd be very happy.

Why did you do this to me? <sigh> Do we have a date for the emergence of the Bushmaster? (apologies in advance if this has been answered already).

[Marco]

Hi Graham,

Just a quickie... Did you go and get the P2 from Convoy Records?

Marco.

[Colin151]

140 watts I believe. It's a Quad 606.

Part of the mystery here is that the Quad 606 has a very high input sensitivity compared to other power amps around. It's nothing whatsoever to do with power output levels. Even a 3 watt per channel 2A3 valve amp can have very high input sensitivity. The Quad 606 input sensitivity is a very high 0.5V for full output rather than the usual 1.6V or so. Its due the the current dumping circuit and its also a deliberate part of the design. Quad preamps such as the 66 or 99 etc have very little gain, because they lack gain stages that can potentially degrade the sound.

I actually sold my 606 because a mate of mine in the USA told me that configuring the output transistors for such high output puts them past their linear point and the sound suffers to some extent. After carefully comparing to some other power amps of normal input sensitivity I did indeed find this was the case with the 606 (I did find the sound was a little crude and rough in comparison). The Quad pre/power amp philosophy seems to be that the preamp is low gain but high quality in terms of SQ and the power amp is high gain but less good sound quality, - the two kind of balance each other out. I used my Quad 606 with a 99 preamp for a while and the sound was very good. I did still run out of volume level though which is why I sold both. The 99 preamp has insanely low max output levels, - you even get far less max output than the unity gain available from a passive preamp (for example). If I had not run out of volume level, I would have likely kept the Quad 99/606 combo. My insensitive Magnepan speakers were part of the issue (the Quad 606 drives them great from a "drive" point of view as it can whack 240 watts into 4 ohms), - its just a shame I ran out of volume (which was 100% due to the 99 preamp). The sound of the 606 with preamps with more gain is not as good as it is with the lower gain Quad preamps.

Anyway (sorry to ramble on a diversion) the reason your Caiman volume control is not used very high up with the Quad 606 is because of the latters high input sensitivity. Even a passive preamp can be used with a Quad 606 and you can get deafening levels. With the Caiman variable out you potentially have even more max volume than with a passive.

I use my Caiman sometimes with its variable out into my NAD and Aragon power amps and it works well. I have to put the pot level pretty high, - around 12 to 3 o clock depending on the material, but the max volume level on the pot is quite a lot more on mine, - around 5 o' clock. Its not an issue in my opinion as I've never run out of volume.

The Caiman variable output has loads more output level than the Quad 99 preamp. The 99 outputs only 0.775 mv. The Caiman does 2V.

[Colin151]

Whether the Caiman variable output has enough vol level would depend on the size of your room, input sensitivity of your power amp, the sensitivity of your speakers, and how loud you listen.......

I have average input sensitivity power amps, insensitive Magnepan speakers, medium sized room, and listen at medium to high levels. I find the Caiman variable output has plenty of output level for me, - I've never needed to turn it up full.

I've tried the variable outs on Caiman, but was not happy with the output volume it was giving me. Basically, I would have to crank the volume control on the Caiman all the way up to get the same loudness I get from my pre-amp at around 10:00 (which is some 20 - 30% of the max volume possible). That just doesn't cut the mustard for me, as I often enjoy my music very loud!

So I'm perfectly happy to learn that Bushmaster had cut the charade and is going fixed only -- less stuff to worry about inside the DAC, way to go!

[Colin151]

As your Quad 520F power amp has pots on it you could try the Caiman fixed output into it and potentially get better sound (as you are omitting the attenuation circuit on the Caiman so getting a purer signal path). Make sure the pots are at minimum on the amp though before doing so. For everyone else with a power amp without pots (which is usually the case), never use the Caiman fixed output into the power amp unattenuated unless you want a nice shock and potentially damage your speakers. The Quad 520F is unusual on a forum like this as its a pro amp that has pots. Most hifi power amps have no pots on them.

I use the Caiman's volume control - it's a ganged stereo pot. The sensitivity pots on the power amp are single channel. I have not tried the Caiman fixed out into the power amp.

[Colin151]

I also have a Quad power amp and have not tried it with the Beresford fixed outs. I worry that without any preamp the volume would be at the highest at default and I might damage my speakers. (I use J.River/PC remote to adjust volume).

Hey that's a nice tidy setup you have there.

NEVER try the Caiman fixed outs into your Quad 606 power amp with any attenuator or preamp in between. There is no way to attenuate the signal and as the 606s has such high input sensitivity damage would v likely to be done to your ears and speakers!.

[Colin151]

I asked Stan about people using the variable outs and he reckons it's the least used part of the DAC. I think a lot of people buy these DACs to use them as an all on one, good quality class A headphone amp. I had a Graham Slee Solo on loan for a friend a while back and did not like the sound at all, - it was far too clinical and a bit lean. I far prefer the Gatorised Caiman which sounds so much more natural and musical, and its so much cheaper.....

I did not have time to listen to the Bushmaster headphone out when Stan stepped by at the weekend (We only used my main system with the Magnepan speakers). I would have loved to try it with my Sennhesiver HD250II and Yamaha YH100 orthdynamic headphones, but perhpas it would not have been a good idea as I would likely now be even more unsatisfied with my Caiman (which still sound great, but in comparison to the Bushmaster...... roll on April!)

I'm surprised that not many people use the variable outs, I would have thought, that for most people, hiding away the large clunky stuff (amps p.amps etc) and the DAC doubling up as a preamp would be half the point. I wonder what percentage of people like the bits on display, especially when it comes to computer based audio?

[northwest]

Hi Graham,

Just a quickie... Did you go and get the P2 from Convoy Records?

Marco.

No, I was snowed in in New York so I have to hang about here for a few days browsing the record stores:-(
Emailed Rupert and I am picking it up Friday

[Marco]

Nice one, dude. Hope you enjoy it

Marco.