Musical Fidelity A5 Amp - Doesn't Sound Right, Near No Bass at All

I brought a used Musical Fidelity A5 Amp a short while ago, and teamed it up with my Dynaudio Audience 50's mainly because I used to own one of their X-A1 amps and loved the sound of them together.

However for a while I suspected that the amp might not be 'right' as it just sounded light. I put it down to me being used to listening to a system with a subwoofer before.... But it just wasn't cutting it, so I added the subwoofer back to the amp and was satisfied with the overall sound.

I've recently moved the stereo and didn't move the sub initially and after playing one record I am convinced there is a fault with my amp making the bass near nothing. It's not the speakers as I experimented and used a different pair and still sounded woefully lacking in bass (and when I say lacking it's like it's not even there).

Question for any A5 owners out there, how does your amp sound for bass? My old X-A1 was awesome, I had to add the X-Tone unit to roll it off at times as the bass was so rich...

What could possibly have gone wrong in the amp and is it fixable? Anyone know a rough idea what the cost might be.

Many thanks for reading

 

Sorry to state the obvious, but have you checked speaker phase? A simple mistake that would cause just the symptom you describe. In my (limited) experience of MF kit its anything but bass light.

 

Are the speakers in phase with each other? Verify the + connections on the amp are connected to the + connectors on the speakers (and the - connections on the amp are connected to the - connectors on the speakers). A quick way to verify is to swap the + and - wire on the back of ONE speaker. If the bass increases, you had them wired out of phase.

 

Maybe the amp is wired out of phase internally?

 

I'm 99.99999% sure that they are in Phase but I am going to swap them about tomorrow to test...

Yeah my experience of MF stuff is anything but bass light also...

Not sure why the internals would be wired out of phase? But that's a good shout.

I've had the speakers recently connected to a Marantz NR surround amp and they kicked out an amazing amount of bass so the Dynaudio's can't be to blame...

Will investigate the phasing then post back...

Thanks for your help so far...

 

So....

I removed all the speaker cables and reattached (including the Hi-Level Subwoofer cable) I looked initially and all wires were connected correctly plus's to plus's , minus to minus etc. When I replaced I put them back I didn't bother putting the sub cable back on and there did seem to be a little more bass, I even tried switching the polarity at the back of the amp (just to see) so + went into - and vice-versa on both speakers, not much difference in sound; actually this might have sounded a little better (but that was probably paranoia)...

The system still doesn't sound great, still bass light (not as much as when the sub was connected and not turned on) and it shouldn't be my hifi is

Michell Gyro SE
Musical Fidelity A5 Amplifier
Dynaudio Audience 50's

So the real thin bass might have been the subwoofer connection and this amp being an integrated dual mono and me having it set up like a Class A, B, A/B amp with a Speakon High Level cable, still in this setup treble was fine, stereo imaging happened and my REL Stampede Sub received and kicked out the Bass... But no bass was coming out of the woofers on the Dynaudio's. I think I probably had the Sub wired up incorrectly, I might look to see if I can run it via the A5's preouts into the LFE input but as there is only one input I'd have to sum the two channels with a Y-Connector and I'd worry about that doing some damage.

So I need to work out why my system sounds bad at the moment. When I used to run it through an X-A1 amp (driving the Dynaudio's) it sounded fantastic - now the A5 'should' be a vast improvement on the X-A1 but as far as I can remember it isn't, (I had my system in storage for a few years while I lived elsewhere and I sold the X-A1 years ago).

Any suggestions as to where to look or what might be wrong would be most welcome.

Thanks!

 

As I understand it, by swapping the + & - on both speakers you’ve just changed absolute phase and probably won’t notice any change in SQ as the cones on L & R channels are in & out in unison.
I used to have a Bryston pre amp where I could do this via the R/C and could not tell the difference.
By swapping + / - on only one channel you are putting them OUT of phase and should notice a big difference akin to the problem you describe.
Do you have a friendly local dealer or a friend who will lend you a different amp to try, swapping out the MF and see what results you get ?

 

Are the leads from the turntable plugged into the PHONO inputs on the back of the A5, or are they plugged into a different input?

(This sounds like a case of the RIAA EQ not being applied).

 

Yeah I did one in Phase one out and it did sound flatter... But I'm still not happy with the sound of the setup...

I will try and see if I can find someone who owns an X-A1 if they would come over and I could test side by side... I know I used to love the X-A1 so that should be a decent comparison.

 

Thanks, the plugs are in the correct Phono stage inputs and the signal is loud enough... I actually haven't tried it with CD so tomorrow I will hook up my Marantz Universal Disc Player (I used it for Blu Rays) and see what that sounds like...

Thanks for sticking with me through this...

 

So I've tested it with my Marantz disc player and, I'm still not that sure... The treble actually sounds a little trill now but that might be because of the player rather than the amp this time... But, I don't have a single repeated album no duplicate CD and LP... So when I am record shopping on Friday I am going to by a copy of Stevie Wonders Talking Book (one of my test LP's) on CD and compare the vinyl and CD quality together..

The Bass does sound a little deeper on with the Marantz playing but that might just be paranoia again. Does anyone think the problem might be the onboard Phono stage of the A5? I can borrow a friends Project Phono stage on Friday also to test that (which I will do anyway).

Will report back on Friday what I find out.

Thanks for reading

 

Hi,

I hope those who replied are still following this thread... Sorry for delay in posting results

So I tried out a copy of Talking Book on my Turntable and on my CD Player and the difference was amazing....

The CD player even though it isn't in the league of the Turntable sounded fuller and with a stack more bass....

I will list my components

Turntable

Michell Gyro SE
Upgraded Rega250 arm (Origin Live)
Grado Prestige Green Cartridge

CD Player

Marantz UD7007

The Turntable should out class the CD Player so I can only imagine that there is something wrong along the chain... I wasn't able to listen to it through the Project Phono Stage as the power pack wasn't supplied, but that can be remedied by the weekend but I remember when I used to play both the Michell and Marantz thorugh my Marantz Surround Amp the Turntable sounded leagues better than the CD player. I used to have a Rega Fono Phono pre-amp.

BIGGER Dave posted

I think this might mean that there is an issue with the phono stage of the amp and I either need to get this fixed or buy a better phono stage. Also the Treble on the CD player sounds superior to the Turntable now and I don't ever remember that being the case, would the possible fault (RIAA EQ) listed above hamper the treble also?

Does anyone else have any other suggestions? Does anyone know if the phono stage of the A5 was poor? If I remember rightly when I was researching amps that the phono stage was reviewed as really impressive...

Any further assistance would be appreciated..

Thanks for following and the support

 

For one thing I wouldn’t expect a ton of bass from bookshelf speakers. The problem could be your turntable or cartridge and the wiring there. Unlikely the amp if you are getting decent sound from CD. You could rule out the phono in the MF by swapping in an outboard phono. Also the cartridge you are using is beneath the rest of your system in my opinion. Nothing against Grado Prestige but I’ve owned a few and they really are just good budget carts.

 

Hi Guildx500 (I have an M-20 myself, love them!)

Agree with you regarding the Grado, however I have used this exact same set up though the Marantz NR Amp (with a phono stage) and it sounded great with loads of bass and the Turntable outstripped the CD player every note! Also these might be bookshelf speakers but they are the exact same speakers I used to use with my X-A1 when I feel in love with the Bass of the Musical Fidelity and Dynaudio combo... So I know there is something 'iffy' with the sound of my setup.

If you could hear the difference when I play the two you'd know it wasn't the cartridges fault as it's like the difference between an AM and FM radio. However you raise a good point about the cartridge wiring so I will look into that...

Once I can get the power supply for the borrowed project phono stage I think I'll be able to isolate the issue if it is the phono stage at fault (or just poor).

I am looking to get a pair of Dynaudio Audience 70 or 72's at some point when I see a pair come up and I have the funds as I do love the sound - but yeah a cartridge upgrade would be something to look into once I've sorted what the current fault is.

Thanks!

 

So got the power supply for the borrowed phonostage..... Hmmmm it doesn't sound any better or worse - I don't think it's the amp/phono stage then.

Taking the point about the Grado Cartridge onboard and knowing I've heard this setup sounding very good I still think that the Table/Arm/Cartridge should always 'out gun' the Marantz UD7007 (which is a very decent player as well)... I am at a loss what to do next or what is not performing

I think I'll remove the cartridge and clean the contacts - redo the alignment, VTF and Tracking weight....

It's probably time I got things serviced anyway....

Any further suggestions from anyone are always welcome. I will look into a new Cartridge (I have a stylus less Goldring 1042 kicking around so might revive that) at some point but only after getting to the bottom of the sound issues...

Thanks for reading