Greetings from Eatonville

Hello all,

I think I posted this in the wrong post originally. So here it goes: I am very new to this site and to audio componets also. Have an issue and don't know how to deal with it. Here is my set up: Martin Logan SL3, Adcom GFA-555ii, Adcom GFP-555ii and Nakamichi PA-5. Is all somewhat new to me, I had the adcom stuff running some polk sda 1c. The Martin Logan sl3 and the Nakamichi PA-5 were given to me. So here is my dilema: I want to run the GFA-555ii for the lows and the Nakamichi PA-5 for the mid/highs via the Adcom GFP-555ii, bi-amping my SL3 but don't know which way is better. The adcom GFP-555ii has 2 sets of pre-out one is direct coupled and the other is capacitively. So far without bi-amping at all both amps sound way better via the capacitively(main) output, because I can control the bass and trebel to my liking. The straight(bypass) output sounds fine, but is kinda flat. So for me to take advantage of the bass and treble adjustment the tone in on my pre-amp has to be pushed in or depressed, however doing so will invert the polarity on the main output. My option 2 is to run some y connectors to my main output. I am soooo confused, please help
 
Welcome to the do it yourself channel.
If both channels of your preamp are inverted at the same time when you push the switch, no problem, they are in phase. RCA jack Y-connectors are $5 at newark.com, plus $5 shipping, worth experimenting with, or running both speakers with a mono-tuner like I am doing now that all the stereo tuners are blah. You'll need two for stereo. You can check for flatness across frequencies with a stereo test CD or LP sweep track. I don't recognize your alphabet list, but a stereo frequency sweep LP (long player record) is CBS Laboratories STR 100. Was that polka records your were talking about? I have 300 lb of records, but no polka albums, alas it makes me dizzy..
Some people hyperventilate at the thought of capacitors in the path of their precious electrons, odd your amp can do it both ways. Crossing zero volts with bipolar electrolytic capacitor sounds a little weird at low volume, but some amps use a single ended power supply and don't cross zero, so with those it is not a problem. Check AB and see what you like. My capacitor coupled single supply ST120 amp and the direct coupled bi-polar supply CS800S sound about the same to me after extensive upgrade (DJoffe) on the ST120, which indicates to me both are performing pretty well.
Please update your profile with a vague location so we have some idea where Eatonville is- you might be close.
 
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My issue is that the adcom GFP-555ii has 2 sets of pre-out one is direct coupled and the other is capacitively. So far without bi-amping at all both amps sound way better via the capacitively(main) output, because I can control the bass and trebel to my liking. The straight(bypass) output sounds fine, but is kinda flat. So for me to take advantage of the bass and treble adjustment the tone in on my pre-amp has to be pushed in or depressed, however doing so will invert the polarity on the main output.
 
absolute polarity

The ear is not very sensitive to the absolute polarity of music. You will notice a properly tightened bass drum hit (like ZZ Top Afterburner) which is inherently and "innie" sounds a lot like a cannon shot (1812 overture, ACDC "For those who are about to rock") which is inherently an "outie". If you stand too close to the cannon, your nose blood vessels can tell the difference, but your ears don't. So don't worry about absolute polarity, anyway. Most speakers these days are bass reflex, which ports the back side of the woofer out a hole to your ears, so your ear will receive a pressure wave either polarity.
A preamp with discrete transistors is usually single power supply class A, so having capacitors in the output does not usually cross zero volts. Preamps don't usually use electrolytic capacitors in the outout anyway, which are the type of capacitor that has stange chemical processes going on at zero volts. The big questions with capacitors are 1. did they buy ones big enough that the rolloff frequency is lower than your ear can hear? (bigger ones cost more). 2. Are they linear enough not to induce distortion into the signal? Most plastic film capacitors made after 1966 are pretty **** linear. Some people claim to hear the difference between one type of plastic and another. I haven't yet. So if you like what you hear with the capacitors, don't feel guilty about it. If your speaker has more than one driver, the signal runs right into a capacitor out there in the black box anyway (the speaker crossover). The is one reason to biamp, as the frequency split is done at low currents in the preamp, where cheap capacitors are adequate, instead of at high currents in the speaker, where saving money on huge capacitors is always a temptation to the speaker designer.