I bought a 5450 years back and it sounds great, but running on my new excelon deck that claims 4v output there are many songs that don't push the amplifier to create enough volume so I have to have the deck pretty high usually. Searching adcom info I could only find that the inputs are a very high impedance which would lead me to believe the deck would have no problem providing sufficient signal to drive the amp. I believe it supposedly only requires just under 1v yet the deck doesn't seem to be able to over drive it so I can drop gains...I have all four amp "gain" pots to max.
I found a phoenix gold six channel line driver and installed it at the deck, even made six 6" long twisted rca cables to go from the deck to the line driver. This configuration has more than enough voltage but now I have to have the line driver turned almost all of the way down to not overdrive the amp. I don't understand how the deck isn't strong enough to drive the amp to its potential yet the line driver is so sensitive I can't use it to potential. It even sounds less musical with the line driver.
There are no phase issues or any other speaker problems and everything is either soldered or better. I would sell the phoenix gold driver and look for some gfi-5400 adcom drivers but am worried they will also be easily overdriven by the deck and have to keep their gains down to not add tons of distortion. I also noticed you can't run normal unbalanced level input and adjust the amp gains, they have to be at max or there will be phase cancellation. Didn't realize until trying to adjust them down for the phoenix gold line driver.
Ugh, I need suggestions for getting this adcom in its sweet spot to still avoid noise yet not have to crank the deck to maximum every time a song with less "volume" plays.
I found a phoenix gold six channel line driver and installed it at the deck, even made six 6" long twisted rca cables to go from the deck to the line driver. This configuration has more than enough voltage but now I have to have the line driver turned almost all of the way down to not overdrive the amp. I don't understand how the deck isn't strong enough to drive the amp to its potential yet the line driver is so sensitive I can't use it to potential. It even sounds less musical with the line driver.
There are no phase issues or any other speaker problems and everything is either soldered or better. I would sell the phoenix gold driver and look for some gfi-5400 adcom drivers but am worried they will also be easily overdriven by the deck and have to keep their gains down to not add tons of distortion. I also noticed you can't run normal unbalanced level input and adjust the amp gains, they have to be at max or there will be phase cancellation. Didn't realize until trying to adjust them down for the phoenix gold line driver.
Ugh, I need suggestions for getting this adcom in its sweet spot to still avoid noise yet not have to crank the deck to maximum every time a song with less "volume" plays.
Have you tried playing a 60Hzsine wave from the deck to see if it's producing the specified output? If you do this, you need to place one probe on the output shield and the other probe on the center conductor.
I haven't tried yet, would also need to try that with the rcas connected to see if the load of the line driver or the amp is dropping it down. The 4v spec is supposedly at 1kohm impedance, the adcom states 13.8k input impedance but that is probably at minimum gain setting. I find it hard to believe my brand new kdx-x998 can't produce the needed "875mv" to drive the adcom to its full potential, even in unbalance mode. I may have to go back to the two a600.2 amps and run one for each pair of components, just didn't want to take up so much room in the car.
\/ Apparently my sig doesn't apply with adcom amps
\/ Apparently my sig doesn't apply with adcom amps
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Hey ppia600, I have one of these that I need to finish the repair on. I will run it when I am done to see what I come up with. Have you looked at the manual on this amp? It seems like they are really down on un-balanced connections. They push there balanced line driver GFI-5400 stating it has an 18 volt output. Makes me wonder if that the only way to really drive one of these amps.
Now I am really curious to finish this amp.
Now I am really curious to finish this amp.
Yes, I'm aware of the adcom manuals and have looked through them. There is a site that lets you peruse and also download them. User Guides - ADCOM-USA
I may try two gfi-5400 units, if that is even possible to find. Still worried the deck will overdrive the balanced adapters or that there may be noise introduced from having to power them with a relay (turn on pop or thump). My amp has the xlr inputs and I don't want to rig more cables trying to use the 5200 units.
Here are two other possiblities that may work.
1- If the output of my phoenix gold line driver isn't grounded on the shield side (balanced), could I not just reconfigure my xlr adapters at the amp to run in balanced mode? Then I could actually turn the line driver up and have higher input voltage. This may work better and allow me to turn the amp "gain" controls down.
2- Buy two of these Rockford Fosgate RF Bld Car Audio Amplifier 2 CH Amp Balanced Line Driver New | eBay and since they are configurable to "balanced" output run them as mentioned above, if my phoenix gold line driver outputs aren't floating.
1- If the output of my phoenix gold line driver isn't grounded on the shield side (balanced), could I not just reconfigure my xlr adapters at the amp to run in balanced mode? Then I could actually turn the line driver up and have higher input voltage. This may work better and allow me to turn the amp "gain" controls down.
2- Buy two of these Rockford Fosgate RF Bld Car Audio Amplifier 2 CH Amp Balanced Line Driver New | eBay and since they are configurable to "balanced" output run them as mentioned above, if my phoenix gold line driver outputs aren't floating.
I was under the impression that my line driver had floating output, but all of the shields are apparently grounded from the unit side, I unplugged all of them and checked with a meter. Maybe it is possible to disconnect that ground from inside the line driver, I didn't see any switch option inside.
The phoenix gold does seem to have floating output but the input and output grounds are the same circuit so I'm not sure how that effects the adcom. I removed the line driver today and will just deal with less volume until I find a solution. It seems like if the deck just had 30% more output voltage that would do the trick. Unfortunately it overdrives the line driver so much that I have to turn it almost all the way down and that seems to affect sq. I will need to find something that will accept a higher voltage and still be able to make the adcom (and my ears) happy.
The TLD66 is for sale, $110 shipped in the US if anyone is interested. Going to find a sale forum and maybe put it on ebay.
The TLD66 is for sale, $110 shipped in the US if anyone is interested. Going to find a sale forum and maybe put it on ebay.
That is interesting. I think the problem, if you can call it that, lies in the amplifiers sensitivity. Especially if there line driver is capable of 16 volts!
No, sorry not yet. I will try to after work tomorrow. I need to find a y splitter so I can plug it inline between the amp and deck and check with them connected, to get the true output. I also need to find my bass mekanik cd, its around here somewhere.
There is also something that I'm wondering about the amp / or the deck. With the music that is "louder" the volume will stabilize at about 30 and if I turn it to 35 (max) it does not increase. There isn't any audible distortion at this level and I'm curious if the deck is doing this to prevent drive distortion or if the amp is doing this purposely or because of some internal issue. ????? The speakers all read pretty much 4 ohms each and none are shorted to chassis. All lights on the amp stay green no matter what and fan speed increases as normal when you are playing it at louder levels, then it slows as you decrease volume and the load drops.
There is also something that I'm wondering about the amp / or the deck. With the music that is "louder" the volume will stabilize at about 30 and if I turn it to 35 (max) it does not increase. There isn't any audible distortion at this level and I'm curious if the deck is doing this to prevent drive distortion or if the amp is doing this purposely or because of some internal issue. ????? The speakers all read pretty much 4 ohms each and none are shorted to chassis. All lights on the amp stay green no matter what and fan speed increases as normal when you are playing it at louder levels, then it slows as you decrease volume and the load drops.
According to Adcom's site and a member, they made the gfi-5400 balanced converters and included them with the gfa-5450 and gfa-5475 amps along with two 20' xlr to xlr cables. That is the next thing I would like to try. Even in the adcom instructions it says only adjust the gains down from full ONLY if you aren't running balanced mode. I may have something pinned incorrectly because when I do that, it just seems the bass disappears like phase is being affected. I've looked at a few diagrams to confirm how I made the xlr to rca adapters and everything seems to check out. You can also touch the individual pins on the amp with the xlr plug disconnected and each one will feedback to its channel. Maybe I have the + and - reversed for each channel somehow, will have to try and find a legit diagram to triple check.
I posted a WTB ad for a gfi-5400 adcom rca>xlr balanced converter, if anyone has one not being used and would like to sell it please let me know. Thanks
Last night I reversed the + and - signal inputs for each channel inside the xlr connector, the sound seems to be crisp on the high end and bass seems to be more defined / in phase. The db level doesn't seem any higher though. I'm still wondering if I should connect the pin 1 inside the xlr connector to pins 3 and 5 like mentioned in another thread. Can anyone confirm or deny whether its the "correct" way to pin them? Thanks for any help.
/\ That is how I connected it last night, then removed the jumper from 1 to 3 and 5. I will try reconnecting it after work this evening.
I tried connecting 1,3, and 5 using only the deck's preamp to drive the amp, and it seemed to decrease sound quality. (possibly imagining things)
I tried connecting the phoenix gold line driver with the 1,3, and 5 ground pins connected and it also didn't sound great. I adjusted gain up and down from both ends and either it would sound like the deck was overdriving the line driver or the line driver was overdriving the amplifier. I couldn't find a good in between.
I tried not using pin 1 on the amplifier end of my adapter cables, of course leaving 2,3,4, and 5 connected to the rca cable pins as normal and then using the line driver and adjusting gains from both ends...still didn't sound great.
The only way music sounds separated and crisp with good bass definition is with the deck driving the amplifier and its gains maxed, but still several songs wont allow a good volume level. I am just going to keep searching for the gfi-5400 balanced converter that comes with these amplifiers originally. If I find one hopefully it maximizes the amp's capabilities, if not I will sell the amp and just run my ppi amps which have zero issues with headroom. I was just hoping to have something smaller with excellent sound quality.
I tried connecting the phoenix gold line driver with the 1,3, and 5 ground pins connected and it also didn't sound great. I adjusted gain up and down from both ends and either it would sound like the deck was overdriving the line driver or the line driver was overdriving the amplifier. I couldn't find a good in between.
I tried not using pin 1 on the amplifier end of my adapter cables, of course leaving 2,3,4, and 5 connected to the rca cable pins as normal and then using the line driver and adjusting gains from both ends...still didn't sound great.
The only way music sounds separated and crisp with good bass definition is with the deck driving the amplifier and its gains maxed, but still several songs wont allow a good volume level. I am just going to keep searching for the gfi-5400 balanced converter that comes with these amplifiers originally. If I find one hopefully it maximizes the amp's capabilities, if not I will sell the amp and just run my ppi amps which have zero issues with headroom. I was just hoping to have something smaller with excellent sound quality.
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Maybe you're driving the amp to full power. It's only 50w/ch. That's only about 3dB greater than the power of a head unit. Are you sure that you're not driving the amp to clipping (check with scope to confirm)?
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