Amplifier Journey

[Floyddroid]

I tend to agree with Jez here. If you can find an A370 and have it fully serviced you may well have what you are looking for. If you want something humble then try a meaty NAD power amp with a decent pre-amp and you will be pleasantly surprised. When you get it right don't Meddle. Keep your eye on the classifieds and your finger on the Pulse. Getting back on the treadmill of changing amps will drive you nuts. I went through a similar experience myself until I eventually bit the bullet and spent the most money I had ever spent on amplifiers and now own my last ever major amp purchase. My advice is to get something that works for you and stick with it or you will end up sailing down the Endless River.

[Floyddroid]

Great thread btw.

[Audio Advent]

May I ask a (silly ?) question ?
What is meant by the terms "fast Bass" & "Slam" when describing how a system sounds ?

I see it as a system being able to portray what's going on in the bass accurately.. simple as that.

If there are resonances in the speaker which make the bass resonate for longer at certain frequencies than is really in the music, then it will sound "slow" and lacking that quick action, fast attack (if it's there in the original). Then also an amplifier may have trouble controlling the bass driver so that it doesn't move back and forth against the physical resistances the driver experiences (e.g. compression of the air in a cabinet) at certain frequencies.

A system could have slam and fast bass at low volumes but one subjective thing is that people mostly only talk about being able to do this at loud volumes where you might experience it more physically.. But the louder you go, then the more your room may be resonating and making the bass appear to be slower etc too.

Then another subjective experience is that bass appears to be faster and to have more "slam" if it is more pronounced in the 60 - 120Hz range (apparently, according to some in the PA/live sound business) so it can actually just be a bad frequency response..

Nothing's ever simple sadly.

[OD1]

I see it as a system being able to portray what's going on in the bass accurately.. simple as that.

If there are resonances in the speaker which make the bass resonate for longer at certain frequencies than is really in the music, then it will sound "slow" and lacking that quick action, fast attack (if it's there in the original). Then also an amplifier may have trouble controlling the bass driver so that it doesn't move back and forth against the physical resistances the driver experiences (e.g. compression of the air in a cabinet) at certain frequencies.

A system could have slam and fast bass at low volumes but one subjective thing is that people mostly only talk about being able to do this at loud volumes where you might experience it more physically.. But the louder you go, then the more your room may be resonating and making the bass appear to be slower etc too.

Then another subjective experience is that bass appears to be faster and to have more "slam" if it is more pronounced in the 60 - 120Hz range (apparently, according to some in the PA/live sound business) so it can actually just be a bad frequency response..

Nothing's ever simple sadly.

If I understand correctly, Shaun you are after a fast punchy bass at domestically acceptable volume levels ?
Would a change of speakers (say 10" dual concentric Tannoys) be worth considering ?

I am thinking :
a. dual concentric to match stereo imaging of your current Kefs,
b. assuming a 10" driver would be "faster" than a 12 or 15 incher, but capable of more "slam" than 8 or 6.5 inch.
c. From another thread you were looking to get some Croft mono blocs, which I think would go well with Tannoys.

Just thinking of alternatives, please ignore if you have already gone down this road ?

Oliver

[Haselsh1]

If I understand correctly, Shaun you are after a fast punchy bass at domestically acceptable volume levels ?
Would a change of speakers (say 10" dual concentric Tannoys) be worth considering ?

I am thinking :
a. dual concentric to match stereo imaging of your current Kefs,
b. assuming a 10" driver would be "faster" than a 12 or 15 incher, but capable of more "slam" than 8 or 6.5 inch.
c. From another thread you were looking to get some Croft mono blocs, which I think would go well with Tannoys.

Just thinking of alternatives, please ignore if you have already gone down this road ?

Oliver

Yes, very worth considering. As previously stated, the only way to really shift air is with big cones. I am currently almost where I want to be but you know, more bass that is tight and fast is always welcome.

[Arkless Electronics]

Several smaller bass units with the same surface area of cones as one big one will move just as much air as a big one ;)

[Haselsh1]

I see it as a system being able to portray what's going on in the bass accurately.. simple as that.

If there are resonances in the speaker which make the bass resonate for longer at certain frequencies than is really in the music, then it will sound "slow" and lacking that quick action, fast attack (if it's there in the original). Then also an amplifier may have trouble controlling the bass driver so that it doesn't move back and forth against the physical resistances the driver experiences (e.g. compression of the air in a cabinet) at certain frequencies.

A system could have slam and fast bass at low volumes but one subjective thing is that people mostly only talk about being able to do this at loud volumes where you might experience it more physically.. But the louder you go, then the more your room may be resonating and making the bass appear to be slower etc too.

Then another subjective experience is that bass appears to be faster and to have more "slam" if it is more pronounced in the 60 - 120Hz range (apparently, according to some in the PA/live sound business) so it can actually just be a bad frequency response..

Nothing's ever simple sadly.

Smaller bass cones equal more attack in the bass and a really decent damping factor tightens things up no end. Masses of current helps with driving those multiple cones and possibly, bi-wiring helps also. Slam and guts only seem to appear at higher volumes possibly due to the inertia of the speaker system in question. Once over that, the whole thing just jumps into tons of life.

[Arkless Electronics]

Smaller bass cones equal more attack in the bass and a really decent damping factor tightens things up no end. Masses of current helps with driving those multiple cones and possibly, bi-wiring helps also. Slam and guts only seem to appear at higher volumes possibly due to the inertia of the speaker system in question. Once over that, the whole thing just jumps into tons of life.

Really? :D

[Haselsh1]

Really? :D

Smaller bass cones have much less reciprocating mass so yes, really. They also have a much lower system inertia so yes, really.

[Haselsh1]

Really? :D

Of course a much lower inertia also means a much 'snappier' attack. That's why some motorcycles have five valves per cylinder. Much smaller and therefore much more responsive. Shifting 15 inches of speaker cone is never going to be the same as shifting three six inch cones. Hence a four by ten speaker cabinet as used by bass players who want that very 'snappy' attack to their sound.

[Haselsh1]

I also remember older Trio amplifiers that had Sigma drive with extra cables and terminals. They had a massive damping factor that was clearly audible in the bass with my QLN loudspeakers. In fact, that was a damn fine amplifier.

[Arkless Electronics]

It depends one hell of a lot on total motor energy as well as mass of cone. No comments on damping factor etc then?

[walpurgis]

Five valve cylinder heads, as you say Shaun, have smaller, lighter valves that can start and stop moving more easily and quickly. This allows engines to rev higher and retain control of the valves. Five valves also offer better use of the cylinder head combustion chamber available surface area than fewer, larger valves, giving a greater effective port area. There is a drawback though (apart from the obvious complexity), smaller valves have less heat dissipation ability and are more likely to get burned, so very accurate fuelling is needed.

Small loudspeaker drivers in multiples to match the surface area of large cones will also stop and start more easily than larger examples. However the resonance of each small driver will be higher, restricting the bass extension. System (cabinet) tuning can help compensate for this. So can equalisation, but that requires more power, so efficiency goes out of the window.

[Arkless Electronics]

Ah I see you just did comment on damping factor... High damping factors (100+) are of zero importance.

[Audio Advent]

Compromises either way. There's no free lunch in physics. Don't ask me to name each set of compromises for each method though :D

[SPS]

Ah I see you just did comment on damping factor... High damping factors (100+) are of zero importance.

My understanding is that over a certain level, current makes little difference as other forces (inductance 1 believe) cancels the effect, in any case the damping from a amplifier only helps to stop the speaker ( if you short out a speaker it brakes it )
Its the acceleration factor that in my view determines the life like qualities of a speaker, and that is a combination of driver attributes , and usually expensive ones
My daughter is a bass player, i have made a few bass rigs for her, the speakers are critical to get the best sound in my experience, and after hearing many other set ups I'm still of the mind that utimately, the heavier the better...

[User211]

The very high surface area of the larger Apogee bass panels provide awesome, fast, detailed and dynamic bass with morer apparent perceived articulation than convertional drivers appear to manage.

Drawbacks are limited excursion (about 5-6mm max on a Duetta), limited max SPL (still enough to cuase hearing damage for prolonged exposure), greater excursion towards the magnet array than towards you (to put it simply more suck than pull).

However despite the single sided magnet array, distortion measurements for such a driver are below many power amps.

I'm pretty convinced that the Kapton film used is a very "snappy" material - more so than mylar. That might go some of the way to explaining why large Apogees sounds so much more dynamic than Maggies, though the fact that Apogees actually have a decent amount of magnets in them no doubt helps too. They are also unquestionably more dynamic than the Analysis Omega - which has sufficient magnets but uses a mylar based bass driver.

Unless you have heard a decently sized recently built or re-built Apogee, you might have a tough time believing what I am saying. Those that have heard mine know what I am saying is true.

[Gazjam]

Five valve cylinder heads, as you say Shaun, have smaller, lighter valves that can start and stop moving more easily and quickly. This allows engines to rev higher and retain control of the valves. Five valves also offer better use of the cylinder head combustion chamber available surface area than fewer, larger valves, giving a greater effective port area. There is a drawback though (apart from the obvious complexity), smaller valves have less heat dissipation ability and are more likely to get burned, so very accurate fuelling is needed.

Small loudspeaker drivers in multiples to match the surface area of large cones will also stop and start more easily than larger examples. However the resonance of each small driver will be higher, restricting the bass extension. System (cabinet) tuning can help compensate for this. So can equalisation, but that requires more power, so efficiency goes out of the window.

Yup, thats how my Eddingdales work.
Four 6 1/2" drivers sharing mid/bass duty have same bass as much larger cone, but react much faster.
Extra attention to construction and cabinet bracing so they are rock solid, even down to just over 30Hz.

Weird thing is, the bass is rearranging your innards but the cones hardly move. :scratch:
Easy to drive at 94db so maybe its that.

[Macca]

Bigger cones ultimately give a more effortless sound. I don't think there is any way around that no matter how many smaller drivers you use.

[Gazjam]

These might sound a bit effortless? :)
http://www.infinity-classics.de/models/IRS-series+Beta+Gamma-Delta-Sigma-Epsilon-1988-95-98/IRS/IRS11.jpg

[walpurgis]

I've actually heard those a couple of times. Impressive, yes. But not what I'd spend that sort of money on (if I had it that is).

[Gazjam]

Me neither!

[struth]

These might sound a bit effortless? :)
http://www.infinity-classics.de/models/IRS-series+Beta+Gamma-Delta-Sigma-Epsilon-1988-95-98/IRS/IRS11.jpg

Could use those as support pillars for the house!

[Haselsh1]

Bigger cones ultimately give a more effortless sound. I don't think there is any way around that no matter how many smaller drivers you use.

Couldn't agree more Martin. When I used to play bass I used a combination of fifteen inch drivers for shovelling loads of air and ten inch drivers for a really nice, snappy top end. Of course the guitar had active pickups so had a really good built in tone system but I always preferred the ten inch drivers. I just love a really nice punchy bass sound. Also of course the fifteen inch drivers need a lot of moving whereas the ten inch ones tend not to.

[Haselsh1]

Five valve cylinder heads, as you say Shaun, have smaller, lighter valves that can start and stop moving more easily and quickly. This allows engines to rev higher and retain control of the valves. Five valves also offer better use of the cylinder head combustion chamber available surface area than fewer, larger valves, giving a greater effective port area. There is a drawback though (apart from the obvious complexity), smaller valves have less heat dissipation ability and are more likely to get burned, so very accurate fuelling is needed.

Small loudspeaker drivers in multiples to match the surface area of large cones will also stop and start more easily than larger examples. However the resonance of each small driver will be higher, restricting the bass extension. System (cabinet) tuning can help compensate for this. So can equalisation, but that requires more power, so efficiency goes out of the window.

Mmmm... kind of agree with the smaller valve thing but heat dissipation has a lot to do with heat transfer coefficient which in turn has a lot to do with surface area. Five valves per cylinder could have the same surface area as two valves of course. In the same way as three bass units could have the same surface area as one big bass unit but a fraction of the overall inertia.

[OD1]

Would a 10" in a sealed enclosure enhance the speed compared to ported / transmission line ?

I recall a dem (MA RS6 speakers) where the bass went from depth to punch (slam ?) when the ports were plugged with foam.

[danilo]

Wow! That a photo of "Fabio's" gear ??
He's a known Audio Weenie :eyebrows:

[User211]

I've actually heard those a couple of times. Impressive, yes. But not what I'd spend that sort of money on (if I had it that is).

Interesting. Where, when and with what kit? What did they do well and what not?

[Haselsh1]

OK, so using my Croft Micro 25 Basic as a valve only phono stage but into the Samson Servo 600, the sound is bloody awful. Using CD it is damn near everything I want. I cannot imagine why this would be so unless it is a case of valves and trannies not working together..? When I say trannies I actually mean transistors and not cross dressers.

[struth]

whats missing? maybe too low op from croft to satisfy the samson line in? is it out via a tape or out via pre out?

[Firebottle]

What's the input impedance of the Samson?

[struth]

What's the input impedance of the Samson?

15k unbalanced... 1.24v 4dBu sensitivity at 8 ohms.

[Firebottle]

That is a very low impedance to be driving from the Croft, it likes to see 100k.

I think that is the problem with the Croft/Samson pairing.

[Macca]

I paired the Croft Micro-Basic with a Behringer A500 and the result was dreadful.

Same Behringer with a passive pre = lovely sound.

[Haselsh1]

Once again Guys your knowledge and experience is essential. I wasn't using the Croft as a preamp though I was only using it as a valve phono stage taking the line output straight into the Samson and using its left/right gain controls. Also, I have been using the CD player outputs straight into the Samson using its gain controls to minimise on interconnects and a pre. This combination sounds amazing. In fact, the stereo effect is much greater used this way than it was using the Croft as a full blown preamp.

I am currently thinking that I may sell the Croft Micro 25 Basic and invest in a TVC preamp. I sort of like the Glasshouse one which I understand is available ready built...?

[webby]

I like the OP, would like to see more like this; how and why you moved on from amp a to amp b etc. A lot of you on here have pretty high end gear and it'd be interesting to know how you got to that stage. Would maybe need consolidating into another thread though as this is 15 pages already.