Hey guys
I bought a second hand ADCOM GFA 5500 of unknown age. Upon hooking up the speakers I found the bass was too thin. On Nirvana's Smells Like Teen Spirit drum kick had nearly no impact. My a lot weaker integrated amp produces twice as much bass as the adcom which I was expected would be vice versa.
We're about to open the adcom and check the capacitors. Any other suggestions as to what to check?
Thanks!
I bought a second hand ADCOM GFA 5500 of unknown age. Upon hooking up the speakers I found the bass was too thin. On Nirvana's Smells Like Teen Spirit drum kick had nearly no impact. My a lot weaker integrated amp produces twice as much bass as the adcom which I was expected would be vice versa.
We're about to open the adcom and check the capacitors. Any other suggestions as to what to check?
Thanks!
We have desoldered the 8 blue capacitors and measured them. They are between 850 and 920mkF (should be 1000mkF). Could that explain the lack of bass?
C3 on my schematic is 47uF.
880uF is not a standard value. You do have the schematic?
https://www.hifiengine.com/manual_library/adcom/gfa-5500.shtml
880uF is not a standard value. You do have the schematic?
https://www.hifiengine.com/manual_library/adcom/gfa-5500.shtml
There's more than one c3 capacitor. Just found the one you mentioned. Takes a while to unsolder it
Eventually you might find out, that there is nothing wrong with your ADCOM, but you are facing the fact, that is is too good for your (possibly) floppy speakers... 😎 I've seen this phenomena many times in my praxis....
Think about it... Weak amp, weak power supply, high output impedance, = no control on the woofer, nice fat bass.
Then: Hefty amp, tightly regulated supply voltages, low output impedance = too much control, weak bass... If you are in doubt, solder a 1-2.2 Ohm 10 Watt resistor in series with your speaker when using the ADCOM, and see it for yourself...
Think about it... Weak amp, weak power supply, high output impedance, = no control on the woofer, nice fat bass.
Then: Hefty amp, tightly regulated supply voltages, low output impedance = too much control, weak bass... If you are in doubt, solder a 1-2.2 Ohm 10 Watt resistor in series with your speaker when using the ADCOM, and see it for yourself...
You could be right. Though my speakers are commonly regarded as bassy. Never heard of anyone mentioning a lack of bass. I have another amp on order and I will recap the adcom, since there's six bad capacitors in it, so we shall see
So, I got a crown xls 2002 class d amp and it's got the same amount of bass as my integrated amp (though sounding a bit different), which to me confirms that the adcom was faulty.
Hm yes also noticed some amps are bass rich. Some not. For example Polk aidiot sda series.. need lots of juice to sound good. Or design acoustics ps9. On power hungry side.
Only 65 watt/Channel Thst Could Make them Sound Bass Rich Is kenwood ka-70. Or onkyo tx-866. Not big and mighty pieces. Others i tried just could not make these speakers blast bass. (Nakamichi ta-1a, nakamichi re-1, sansui 5900z, luxman r115, luxman rx101. All of the above are 65-85 watts receivers
BUT a 200w+ power amp alway blew serious bass through these power hungry speakers. Yamaha mx1, onkyo m504.
Interesting phenomenon.
Wanted to know how to determine which one will bring more bass into our hearts. Onkyo tx866 is not too heavy. Pretty sure nakamichi re-1 is heavier. And yet tx866 produced more bass on power hungry speakers. Transformer size?..
What I was trying to say.
It's not surprising That huge power amp with stellar woofer control damping factor of 200-300 drives these speakers bass rich
But then there are much less powerful amps with dumping factor of about 40-50 and still produce bass just like power amp. And some a bit more powerful amps That can't get the woofer to move enough
It's not surprising That huge power amp with stellar woofer control damping factor of 200-300 drives these speakers bass rich
But then there are much less powerful amps with dumping factor of about 40-50 and still produce bass just like power amp. And some a bit more powerful amps That can't get the woofer to move enough
A well made and non faulty amp should sound linear (or close to that) regardless of it's power/current specs. Inadequate bass indicates either a faulty amp or an amp incapable of driving the connected speakers. The incapability of driving speakers may or may not show as inflated bass, but in such cases bass is supposedly poorly controlled and is lacking details/resolution.
convention wisdom holds that low impedance/sensitivity speakers such as Dynaudio require amplifiers with high damping factor to drive the speakers properly. Yet two of commonly recognized good partners for the dyn's are densen and naim and both have low damping factor (100 or below). To me it tells that there's no simple correlation between speakers and amp's damping factor.
Hi guys, just to give you an update. We replaced 8 large blue capacitors and 3 small capacitors in each channel, and the bass is back. The adcom turned out to be very capable amplifier in terms of bass control.
Also I wanna add, that I replaced the 4 "beer can" capacitors with 22000uf ones, this made no audible difference, also surprisingly the old "beer cans" turned out to be in a very good shape (17900-17990uf each, low ESR), meaning you probably shouldn't worry about them at all.