Well folks...
Unfortunately, I'm starting to suspect I might have bought a lemon.
For one, this thing is not terribly-loud. Yes, I have the input pad switched "on", since my bass has active electronics, but I have the Gain control dimed and the Master cranked to 12 noon-- I won't go any higher because my cab is rated to just 500W (at 8 ohms)-- and I'm barely outside the realm of "bedroom volume". I haven't even ticked-off my neighbors yet! When I switch the Input Pad to "off", the signal gets too "hot" and I find myself rolling-back the Gain control, so no real increase in volume, when all is said and done. Is there something else I should look at?
Secondly, the "Peak Limit" and "Protect" LED's turn on whenever I hit the "Standby" button, and they stay on until about a second or two after I turn the "Standby" to Off. Is this normal? There is no mention of this phenomenon in the manual...
My apologies for bringing this to a public forum, but I'd like to make sure I'm not "in the wrong" before I alert the seller. Any feedback, one way or the other, would be appreciated!
Thanks in advance!
So the deal with the pad is that it drops the signal strength by 12db. That's a drop of more than half the strength of the original signal. The idea behind it is that some (OK maybe a LOT) of active bases put out a really strong signal because they have a battery powered preamp instead of just passive controls. Using one of these high-output bases gives you very little granularity in the gain adjustment. Without a pad button you may not be able to turn your gain control beyond 8 o'clock or 8:30. The pad control drops the strength of that incoming signal so instead of 8 o'clock the gain-set light starts flashing somewhere between about 10 o'clock and 2 o'clock. Now you can make small adjustments in the gain control to better control the resulting sound.
Before you set the gain though you need to set all the EQ to straight up noon (flat), bypass the compressor, and turn the shape control off. That will give you a clean, un-boosted, un-cut, signal to start with. Also, turn the master down to around 8 o'clock, or just turn it all the way off. Then we want to get a baseline adjustment on the gain.
Sounds like your bass doesn't have a super hot signal, especially since you don't get any flashing of the gain-set light with the Gain control dimed. So turn the pad off. Turn the gain control to about 10 o'clock and start playing your bass. If the gain-set light doesn't flash when you are playing your lowest and loudest notes, then you need to turn it up a bit. Slowly turn the gain up until the gain-set light starts flashing as you play the lowest and loudest parts of your performance. If you're digging into your strings and it's not flashing, you need to turn the gain up.
Conversely, if that gain set light comes on and stays one, the gain is too much and you need to reduce it. It's a Goldilocks thing - not too little, not too much, just right! Ideally you want to have that light dance when you really get into it, but you don't want it to come on and just stay on. When you get that light dancing you are sending a strong and clean signal to the power section. When it comes on and stays on you are sending a distorted signal to the power section. If it never comes on, you are sending too-weak of a signal to the power section.
Sending too weak of a signal will not only give you very low volume, it will often give you a noisy signal too. Back in the days of LP Records, a 55 to 1 ratio of signal to noise (55db:1db) was considered hi-fidelity. That's why the records (except for K-Tel) sounded so good. But as soon as the music stopped, you hear the pulsing noise from the needle tracking a groove or perhaps some wow or rumble from a less than excellent turntable. If you don't send enough signal to the power section than the tiny amount of noise you might get from the power section becomes a much larger portion of what you hear.
Once you have that baseline set on the gain, then go ahead and make your EQ adjustments. Turn your master back up above bedroom levels. The human ear doesn't hear the bass and treble as well at low levels (hence the "loudness" button on stereos) but hears the mids just fine. If you set your EQ for bedroom levels, it won't sound good at gig levels. So for this part, turn it up loud enough to play a small venue.
The EQ controls are capable of boosting or cutting up to 15db, which is a lot! A very small movement in the control will make a noticeable difference in your sound. So slowly adjust your EQ to achieve your desired sound. Once you've got the sound you want, check the gain. Boosting and cutting the EQ will have an effect on the gain signal. If that gain-set light isn't dancing when it should, turn it up until it dances. More likely, if it comes on and stays on without flashing, turn it down until it dances again.
Now about that standby button. It's purpose is not what you are thinking of or using it for. The traditional use of "standby" switch was to reduce the current going to the tubes and prevent the signal from going to the output transformer. That supposedly gave you longer tube life. The DNA amps are class D amps (power switching) and not tube amps at all and that standby button is for a different use.
That standby button is there so you can turn off the power section while still using the preamp to send out a signal. Most commonly that's for use when recording where you don't want any sound coming out of your cab and you already have the cab set up in the studio. Most commonly in pro studios they will run both a DI from the amp and mic the cab, and then mix those signals together as needed to get what the sound they want out of it. Sometimes using a cab in too small a room or too close a proximity to other instruments will result in unwanted cross-talk of mic'd instruments. That's where the standby button on your amp works. The preamp is still functional with the standby engaged and a signal will definitely come out of the DI connection, but there is no signal going to the power section. The amplifier (power section) is not operating when the "standby" is on.
You said that when the standby was on the peak and protect lights come on. I'm not sure if those are supposed to be on or not with the standby engaged. Perhaps @Bassmann1968 will pop in here with an answer. I suppose it's possible that the protect circuitry is the method used to stop the power section from working, but I just don't know. That peak light is supposed to come on when the output amplifier exceeds 0.01% total harmonic distortion THD). That is still below the actual maximum output of the power section but is an indicator that your signal clarity is degrading and will do so very quickly after that point. You probably won't hear any noise from the amp even when that comes on because anything below 1.0% THD is still considered high-fidelity.
One thing that can normally cause a peak indicator to light up is an EQ that is boosted too high. Usually that happens when the bass is boosted way up. If you have the footswitch for the amp, you can just step on the bypass tone switch which puts all the EQ at the flat position to check that out. If the light goes out when you do that and comes back on once you disengage the tone bypass, then that's what's happening. I kind of doubt that's what's happening, but I just don't know enough about the circuitry to address that. If @Bassmann1968 pops in here, he may very well have the answer.
Hopefully we can get this sussed out so you don't have to take it to a tech. That amp actually puts out an incredibly clean, clear signal and is really loud. It will put out 675-watts rms into your 8Ω cab and another 675-watts into a second 8Ω cab.
