hey laddies & lassies,
fyi. normally i don't really switch my amps off but after receiving our last electricity bills we started to pay attention to switching off machines we weren't using. So for a while i switched off my gainclone at night. Strange thing is, when i switched it on in the morning it sounds like sh*t. If i leave it on for say an hour or so, it sounds right again, no matter whether i play music or not.
Directly after switch on there's almost no bass at all and highs are harsh and too bright. This fades away after an hour or so and it sounds right again. strange!
Does anyone share my experience?
fyi. normally i don't really switch my amps off but after receiving our last electricity bills we started to pay attention to switching off machines we weren't using. So for a while i switched off my gainclone at night. Strange thing is, when i switched it on in the morning it sounds like sh*t. If i leave it on for say an hour or so, it sounds right again, no matter whether i play music or not.
Directly after switch on there's almost no bass at all and highs are harsh and too bright. This fades away after an hour or so and it sounds right again. strange!
Does anyone share my experience?
matjans said:
As a Belgian living in the USA I can speak freely about this.
It's the over consumption of Heineken beer!!!!!
As you stated "in the morning' meaning while having a hang-over!!!!!
Try Stella beer instead, the sound will surely be mych richer and fuller! for sure!
Jean-Pierre
cheers !!!!
Matjan,
Yes, I agree. On my Gaincard, the sound seems to take several days to get back to "sounding right" after it's been turned off.
To tell you the truth, when I first bought my Gaincard, it took more like three weeks before it became really musical. Before that I thought I had made a mistake with it's purchase.
I don't know why this happens, but it seems to take the GC much longer to settle than anything else I've ever used. I leave mine on all the time as the 25 watt model runs quite cool.
I owned the 50 watt model for a while, and that ran significantly hotter. I would consider shutting that one off if not using it constantly.
All of this makes me wonder if the root of the effect is in the power supply or the amp circuit.
I'm considering a battery supply with the clone I'm working on, but I wonder how this phenomenom would effect the sound, since the amp would have to be shut off to conserve battery life.
Oh, I like pale ale, myself.
Best,
KT
Yes, I agree. On my Gaincard, the sound seems to take several days to get back to "sounding right" after it's been turned off.
To tell you the truth, when I first bought my Gaincard, it took more like three weeks before it became really musical. Before that I thought I had made a mistake with it's purchase.
I don't know why this happens, but it seems to take the GC much longer to settle than anything else I've ever used. I leave mine on all the time as the 25 watt model runs quite cool.
I owned the 50 watt model for a while, and that ran significantly hotter. I would consider shutting that one off if not using it constantly.
All of this makes me wonder if the root of the effect is in the power supply or the amp circuit.
I'm considering a battery supply with the clone I'm working on, but I wonder how this phenomenom would effect the sound, since the amp would have to be shut off to conserve battery life.
Oh, I like pale ale, myself.
Best,
KT
When I first switched on my quick'n'dirty GainClone it sounded just that. And cheap too. Having put it away, I retreated to the familiar surrounding of the tubes. However, a few months ago I took it out, and after a feeble Peter Daniel treatment, did note that it takes around 20 days to break-in and few hours to warm-up. Thereafter, its just marvellous.
Ahh…nothing like pure audiophile grade Kingfisher lager for me.Ropie said:
KT said:
KT,
just leave it connected to the batteries all the time. I do that and the batteries (I use 2x 12V 7.2Ah SLAs paralled per rail, eight pieces altogether for the whole amp) still lasts for weeks (stays above 12V), although I make it a point to recharge every Sat night so as not to unduly stress my chargers.
Or you can leave the charger(s) on all the time, switching them off only when listening. In fact, this is the recommended scheme for SLAs which like to be floated at a constant voltage (of around 13.6V, this value depending on ambient temp). In this scenerio, do keep the charger(s) physically away from the batteries as the heat from the charger(s) could shorten batteries life over the long haul.
Probably a dumb idea, but how's it sound to you?
Hi Matjans;
If I understand your situation correctly, it doesn't matter whether or not you're listening to the amp while it's "warming up" - it's just a question of whether you leave it running 24/7 or not. Thus, if it's been left on for the last few days and you put on some music, it sounds fine - but if you have to start it up cold to play music, then the sound quality is substandard.
If so, could it be that there's some ringing going on in your trafo/PS assembly? Perhaps on first switchon the big transient pulse as the caps charge sets up a small oscillation in the PS (since there's going to be R,L, and C present in the circuit, I could imagine it working like an oscillator...). Just an idea, but mightn't that account for grainy sound (RF artifacts due to the ringing) and the poor bass (power lost in oscillation between the trafo and the caps)? As it settles down over time, then the symptoms would disappear....
Anyway, if that crazy notion is actually something like right, perhaps you could try ramping up the AC slowly with a variac. If the problem disappears then you can proceed from there....
Good luck with it!
All the best,
Morse
Hi Matjans;
If I understand your situation correctly, it doesn't matter whether or not you're listening to the amp while it's "warming up" - it's just a question of whether you leave it running 24/7 or not. Thus, if it's been left on for the last few days and you put on some music, it sounds fine - but if you have to start it up cold to play music, then the sound quality is substandard.
If so, could it be that there's some ringing going on in your trafo/PS assembly? Perhaps on first switchon the big transient pulse as the caps charge sets up a small oscillation in the PS (since there's going to be R,L, and C present in the circuit, I could imagine it working like an oscillator...). Just an idea, but mightn't that account for grainy sound (RF artifacts due to the ringing) and the poor bass (power lost in oscillation between the trafo and the caps)? As it settles down over time, then the symptoms would disappear....
Anyway, if that crazy notion is actually something like right, perhaps you could try ramping up the AC slowly with a variac. If the problem disappears then you can proceed from there....
Good luck with it!
All the best,
Morse
this should give you enough information.
input cap is a black gate N 4,7uF 50v i believe
feedback loop is 22k caddock / 1k riken
r1 is standard carbon film 22k
caps are 1000uF black gates
that's it
edit: eagle didn't have the 3875 so i substituted a 1875.
An externally hosted image should be here but it was not working when we last tested it.
input cap is a black gate N 4,7uF 50v i believe
feedback loop is 22k caddock / 1k riken
r1 is standard carbon film 22k
caps are 1000uF black gates
that's it
edit: eagle didn't have the 3875 so i substituted a 1875.
matjans said:
Hi Mate
Just a thought, but do you always turn it on at the same time each day? If so, you could have a problem with a noisy mains supply. I think Grataku once made some measurements of how noisy the mains supply is at various times where he lives, it was very interesting to note the changes throughout the day.
BTW, (Mod cap on), could you try to express yourself without swearing, merely adding an asterisk doesn't really make much difference to the principles involved...
Hi Matjans;
Hmmm, if it's not the PS, then I think your idea that there's a warmup time required may be the right one.
Just to expand on what I'd posted earlier, any time you have an RLC series circuit you will find that there's a resonant frequency to it, due to the relation Z = (R^2 + (XL-XC)^2)^1/2 where Z is impedence, R is resistance, XL is 2*pi*freq*inductance and XC is 1/(2*pi*freq*capacitance). Particularly if the "R" value in the circuit is very low, you'll find resonance to be quite pronounced at freq = (4*pi^2*capacitance*inductance)^-1/2. This is because the "R" acts to damp out the amplitude of the oscillations, and in it's absence, there's no damping term. Thus, if you treat a PS circuit as being made up of several "loops" (each representing a current under Kirchkov's rules), you'll see that each loop will have a tendency to "ring" at some freq, if excited (like "ringing a bell"). If you're unlucky enough to have built one in which you have several "loops" (say a CLCLC "2 pi" filter) that all resonate at the same freq then that could be a problem....though from the sounds of it you have a simple capacitance filter with decoupling caps at the chips.
'Course that's all theory, so what do I know!
Good luck on finding a solution and all the best,
Morse
Hmmm, if it's not the PS, then I think your idea that there's a warmup time required may be the right one.
Just to expand on what I'd posted earlier, any time you have an RLC series circuit you will find that there's a resonant frequency to it, due to the relation Z = (R^2 + (XL-XC)^2)^1/2 where Z is impedence, R is resistance, XL is 2*pi*freq*inductance and XC is 1/(2*pi*freq*capacitance). Particularly if the "R" value in the circuit is very low, you'll find resonance to be quite pronounced at freq = (4*pi^2*capacitance*inductance)^-1/2. This is because the "R" acts to damp out the amplitude of the oscillations, and in it's absence, there's no damping term. Thus, if you treat a PS circuit as being made up of several "loops" (each representing a current under Kirchkov's rules), you'll see that each loop will have a tendency to "ring" at some freq, if excited (like "ringing a bell"). If you're unlucky enough to have built one in which you have several "loops" (say a CLCLC "2 pi" filter) that all resonate at the same freq then that could be a problem....though from the sounds of it you have a simple capacitance filter with decoupling caps at the chips.
'Course that's all theory, so what do I know!
Good luck on finding a solution and all the best,
Morse
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