apassgear said:
Thanks for the reply Babo
On my amps I also use wirewounds as source resistors but was wondering why others like Nelson avoid using them on this position and though it might be because of inductance and or sonic reasons.
you know how often Papa sez :"I have them plenty in stock"
my guess is that this reason is at least equally important as possible sonic benefits
if any
in crap designs everything is too much important........
The inductance in wire wound resistors can be a problem in terms of stability. It is generally too small to cause sonic trouble.
That said, there are so many good non-inductive resistors out there, why use the inductive ones? The only place I can see any benefit is in, say, a CRC filter in a power supply. Even then, the amount of inductance is so minor as to be of little or no benefit.
Grey
That said, there are so many good non-inductive resistors out there, why use the inductive ones? The only place I can see any benefit is in, say, a CRC filter in a power supply. Even then, the amount of inductance is so minor as to be of little or no benefit.
Grey
Sorry for the noob question, but what type of caps may be used for the various positions (eg metal film, electrolytic etc). At the moment I'm guessing that c3 and c4 can be electrolytic, and c1, c2, c5 are metal film?
I have some 10uf paper in oil caps lying around, could they be used for c5 (if there's any benefit over metal film)? Also, can electrolytic be used in c1, c2, c5 because that's slightly more convenient than metal film
Sorry again for such noob questions, but on the bright side I'll soon be done and there will be another f2 in the world!
I have some 10uf paper in oil caps lying around, could they be used for c5 (if there's any benefit over metal film)? Also, can electrolytic be used in c1, c2, c5 because that's slightly more convenient than metal film
Sorry again for such noob questions, but on the bright side I'll soon be done and there will be another f2 in the world!
C3, C4 are definitely electrolytes.
Avoid electrolytes for C1, C2 as they are in the signal path and said to sound less good.
I used polyester MKT series but polypropylene should even be better.
As for C5, I believe your paper in oil will do just fine if the minimum voltage rating is adequate.
/Hugo
Avoid electrolytes for C1, C2 as they are in the signal path and said to sound less good.
I used polyester MKT series but polypropylene should even be better.
As for C5, I believe your paper in oil will do just fine if the minimum voltage rating is adequate.
/Hugo
Thanks Hugo
For everyone, here is my board layout. I was hoping someone would be able to check over it quickly to make sure it's laid out properly before I switch the amp on. It looks right to me, but I'm fairly new to this and doing the layout has been a headache.. plus it cost me $45 to ship the parts to austraila! I don't wanna fry it this quickly and have to order more!
If it's right, some newbies may find it helpful in their builds. It's just designed to use stripboard/matrixboard
Thanks in advance for anyone who is able to help out.
For everyone, here is my board layout. I was hoping someone would be able to check over it quickly to make sure it's laid out properly before I switch the amp on. It looks right to me, but I'm fairly new to this and doing the layout has been a headache.. plus it cost me $45 to ship the parts to austraila! I don't wanna fry it this quickly and have to order more!
If it's right, some newbies may find it helpful in their builds. It's just designed to use stripboard/matrixboard
Thanks in advance for anyone who is able to help out.
An externally hosted image should be here but it was not working when we last tested it.
I found a mistake on my own board :/ here is the updated one
An externally hosted image should be here but it was not working when we last tested it.
Hi,
I want to build this amplifier for my D58 ES. I have built some tube amplifiers but it's my first mos amplifier so i have some questions:
About resistors, the R2 value is 221 Ohm. Is a 220 ohm OK?
There is 2,21 k or 47,5 Ohm. I'm surprised. Is it possible to put 2,2K for R21 or 47 Ohm for R3 for example?
For the power supplie, i want to built one like the F1, is it OK or is it better to wait the N.Pass article?
Thank's
A Bientôt
Bruno
I want to build this amplifier for my D58 ES. I have built some tube amplifiers but it's my first mos amplifier so i have some questions:
About resistors, the R2 value is 221 Ohm. Is a 220 ohm OK?
There is 2,21 k or 47,5 Ohm. I'm surprised. Is it possible to put 2,2K for R21 or 47 Ohm for R3 for example?
For the power supplie, i want to built one like the F1, is it OK or is it better to wait the N.Pass article?
Thank's
A Bientôt
Bruno
Okay the basic PSU and one channel of my F2 is done!! A few questions though.. (you saw it coming)
1) There's a constant (but reasonably quiet) hum going on. However I haven't yet connected up the 0.0033uf cap in the F1 PSU (out of laziness because it's legs are too small to do p2p at the moment). Is this constant hum likely caused by this, or something simple such as transformer placement? Or would such a hum be caused by an actual mistake? Previously I had removed the earth and the hum was gone. Also, the hum is gone if its using a discman as source, so i'm worried it could be a ground loop or something (except my source and amp are both on the same outlet)
2) In the 240v F1 PSU how is "TH" wired (I'm using a 240v 18-0-18 transformer with two input wires and 4 output wires)
3) Initially we connected the 24V DC wires from the power supply the wrong way (ie positive to negative), which caused a quiet cracking sound and some smoke. We quickly turned it off and corrected the problem, and since then everything seems to be operating fine.. but I'm still paranoid. Is there anything I could've fried? I'm somewhat worried about the ZXT550, because...
4) Out of curiosity I hooked up my very cheap 3-way sony bookshelf speakers expecting them to sound totally weird... but they sounded totally FINE. Again, I'm paranoid. Could my amp be operating in normal voltage mode somehow? (fried ztx?) or do my sony's just lack a proper xover?
5) How to set the bias? Currently I'm connecting the multimeter to the GND and the opposite leg of the output capacitor (ie the leg thats NOT going to speaker output) and setting the trimpot until I get a reading of half the PSU voltage (ie half of 24v). Correct?
Thanks for the help. Here's a photo of it in action
1) There's a constant (but reasonably quiet) hum going on. However I haven't yet connected up the 0.0033uf cap in the F1 PSU (out of laziness because it's legs are too small to do p2p at the moment). Is this constant hum likely caused by this, or something simple such as transformer placement? Or would such a hum be caused by an actual mistake? Previously I had removed the earth and the hum was gone. Also, the hum is gone if its using a discman as source, so i'm worried it could be a ground loop or something (except my source and amp are both on the same outlet)
2) In the 240v F1 PSU how is "TH" wired (I'm using a 240v 18-0-18 transformer with two input wires and 4 output wires)
3) Initially we connected the 24V DC wires from the power supply the wrong way (ie positive to negative), which caused a quiet cracking sound and some smoke. We quickly turned it off and corrected the problem, and since then everything seems to be operating fine.. but I'm still paranoid. Is there anything I could've fried? I'm somewhat worried about the ZXT550, because...
4) Out of curiosity I hooked up my very cheap 3-way sony bookshelf speakers expecting them to sound totally weird... but they sounded totally FINE. Again, I'm paranoid. Could my amp be operating in normal voltage mode somehow? (fried ztx?) or do my sony's just lack a proper xover?
5) How to set the bias? Currently I'm connecting the multimeter to the GND and the opposite leg of the output capacitor (ie the leg thats NOT going to speaker output) and setting the trimpot until I get a reading of half the PSU voltage (ie half of 24v). Correct?
Thanks for the help. Here's a photo of it in action
An externally hosted image should be here but it was not working when we last tested it.
