Hi K-amps,
I guess you need to take a look inside. These transistors are rarely used for anything but muting. How old is your preamp? I can't seem to find anything but newer gear. I have not found a schematic on it at all.
If this is a newer unit (newer than, say 1995) it may very well use these parts.
-Chris
I guess you need to take a look inside. These transistors are rarely used for anything but muting. How old is your preamp? I can't seem to find anything but newer gear. I have not found a schematic on it at all.
If this is a newer unit (newer than, say 1995) it may very well use these parts.
-Chris
anatech said:
I did nothing but bloomin' older generation op-amps
I guess I will have to look harder. Before i knew about the 1.2vdc at the outputs, I connected it to a true DC coupled Krell KSA-250.... it nearly took out my speakers before I turned it of.... it was quite a shock, lol becuase with the Adcom 555ii beofre it, I never saw DC at the outputs because of the 1uF used in the Adcom inputs.
Yeah. I had a friend that had a Krell set. The pre decided to throw some DC out & he almost lost some PSB Stratus Gold i 's. Op amp when bad in the pre.
But who in their right mind DC couples an amp ????! I guess the folks at Krell use magic part too. No offset protection on these either (at least it didn't trip). I am not impressed.
-Chris
But who in their right mind DC couples an amp ????! I guess the folks at Krell use magic part too. No offset protection on these either (at least it didn't trip). I am not impressed.
-Chris
Hi Andrew,
I'll buy that, but the preamp in question has no coupling cap, nor does the power amp. My Marantz 300DC does have a coupling cap with the option of direct coupling.
Most rooms will not support the bottom few octaves, never mind the speakers. If your lower corner is 10~15 Hz I wouldn't worry about it too much. Unless you have a huge room and a lower cutoff of 10~15 Hz with your speakers. This might be a room the size of most of my house!
-Chris
I'll buy that, but the preamp in question has no coupling cap, nor does the power amp. My Marantz 300DC does have a coupling cap with the option of direct coupling.
Most rooms will not support the bottom few octaves, never mind the speakers. If your lower corner is 10~15 Hz I wouldn't worry about it too much. Unless you have a huge room and a lower cutoff of 10~15 Hz with your speakers. This might be a room the size of most of my house!
-Chris
Guys, If Krell chooses to have no input coupling cap, let them. They thought at the time that it introduces distortion... maybe it does.
I would not like to use the argument that a DC on the preamp will destroy speakers... thats the preamp's fault not the power amp's fault. The power amp is faithfully passing the signal sent by the pre-amp and thats what it should do.
I would not like to use the argument that a DC on the preamp will destroy speakers... thats the preamp's fault not the power amp's fault. The power amp is faithfully passing the signal sent by the pre-amp and thats what it should do.
Okay, I'll buy that argument. But since DC on the output is not only an abnormal situation, but a dangerous situation, shouldn't the amp have detected this removed the output from the load in some manner? BTW, this is the same response that Bryston gave me after one of their amps went DC, except they refused to accept it was their amp, "our amps don't fail". But there it sat, unconnected to anything with full supply across the output terminals of one channel. A burn out in the vas section - not outputs or drivers
Give me a break. The DC condition did cause a fire that had to be extinguished. It was a pro gig, sound re-enforcement for a meeting indoors (not an abusive situation). A professional company did the setup and ran the board. Now, Bryston recommended leaving the amps on 24/7. Do you want this amp in your house while you are sleeping - or at work?
I think it is next to criminal to not include an effective method of protecting the speaker load. (Bryston suggested installing fuses in the speaker leads).
It is a fact of life that sometimes things fail on their own, or with encouragement. It is our responsibility that the damage goes no further. Is there argreement on that point? If so, why not?
-Chris
Give me a break. The DC condition did cause a fire that had to be extinguished. It was a pro gig, sound re-enforcement for a meeting indoors (not an abusive situation). A professional company did the setup and ran the board. Now, Bryston recommended leaving the amps on 24/7. Do you want this amp in your house while you are sleeping - or at work?
I think it is next to criminal to not include an effective method of protecting the speaker load. (Bryston suggested installing fuses in the speaker leads).
It is a fact of life that sometimes things fail on their own, or with encouragement. It is our responsibility that the damage goes no further. Is there argreement on that point? If so, why not?
-Chris
Hi K-amps,
Understood. For the fanatical who don't like switches, provide a cap coupled input and a direct input. That will satisfy most for this I think.
Might work as a voltage source. Methinks you just insulted the fine folks at Krell.
Oh well, better send them an apology quick before they hunt you down!
-Chris
Understood. For the fanatical who don't like switches, provide a cap coupled input and a direct input. That will satisfy most for this I think.
Might work as a voltage source. Methinks you just insulted the fine folks at Krell.
Oh well, better send them an apology quick before they hunt you down! -Chris
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