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Old 9th August 2011, 09:57 PM   #101
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Quote:
Originally Posted by HornTube View Post
3. The wirewound resistors in your poweramp are crap. Change them to Mills.
4. The Jensen caps sounding lame and not very dynamic with deep stage but also narrower stage width, change them to Mundorf Supreme or DynamiCap.
5. The other cap C4 don't look good, change them to Epcos, Elna or Nichicon.
@hornguy:
Hi do you recommend mundorf mcap supreme more then dynamicap?

3-also im not sure what is the wireround resistor could you point them out to me as I want to buy the mills ones but im not sure which reisstor is a wireround resistor.

4-To swap the jensen caps. they are 0.22uf. Could I get bigger values like 1.uf values mundorf mcap supreme or I should keep the values as close as possible as the jensen? So I keep 0.22 uf or could go with higher values for a better sound?

5-c4 cap value is 150uf 450v: so elna silmic would be okay. but can I take a higher value? because theres no 150 uf only 220 or 100uf so which one should I take?


I just need those final answer from you horntube or anyone else that can confirm with me the caps Ill buy

thanks a lot for your help

Jason
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Old 11th August 2011, 07:05 PM   #102
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Would you guys Consider adding a few dB of negative feedback to the Amp?
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Old 11th August 2011, 07:23 PM   #103
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wrong thread
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Old 11th August 2011, 08:19 PM   #104
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Murphy!

Do not replace the .22 caps with a different value.

Also do not replace the 150uf 450v caps with Silmic's, Silmic's do not come in a high enough voltage for that replacement.

If you change components for different value ones you will be in all sorts of trouble in most cases.

Keep the values of caps the same, both the 'uf' value and 'voltage' value.

Same goes for resistors, 'ohms' and 'wattage' must be correct for the job.

If changing values you need to understand why you are doing it, first.

Edit:Just another bit, negative feedback? I wouldn't unless there is a good reason to do so.

Last edited by data; 11th August 2011 at 08:29 PM.
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Old 11th September 2012, 01:58 AM   #105
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Quote:
Originally Posted by richwalters View Post
In that case they are reacting exactly as they should do by being proper resistors with ideal temp coefficient. It's the peak current issue that causes alot of the conventional film types to soften up on impulse transients which they cannot handle.
richy
Remember, the "normal" wire-wounds are plain normal but the Mills are highest military standard. I do not think that Mills are softening the sound. From my experience most cheap parts do sound restrained, like cheap RCA plugs, cheap metalfilm resistors etc...
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Old 11th September 2012, 02:06 AM   #106
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Quote:
Originally Posted by data View Post
Murphy!

Do not replace the .22 caps with a different value.

Also do not replace the 150uf 450v caps with Silmic's, Silmic's do not come in a high enough voltage for that replacement.

If you change components for different value ones you will be in all sorts of trouble in most cases.

Keep the values of caps the same, both the 'uf' value and 'voltage' value.

Same goes for resistors, 'ohms' and 'wattage' must be correct for the job.

If changing values you need to understand why you are doing it, first.

Edit:Just another bit, negative feedback? I wouldn't unless there is a good reason to do so.
Yep, but the .22 can be larger in value. But if you make it too high it will start to sound thick and slower.
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Old 11th September 2012, 02:07 AM   #107
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Quote:
Originally Posted by murphythecat8 View Post
5-c4 cap value is 150uf 450v: so elna silmic would be okay. but can I take a higher value? because theres no 150 uf only 220 or 100uf so which one should I take?
Or go with a film cap for a big upgrade... Check out ClarityCap's TC line of powers supply film caps. The 110 uF cap should be fine.
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Old 11th September 2012, 03:23 AM   #108
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I would add some film bypass resistors to those tin can caps.
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Old 18th September 2012, 11:52 PM   #109
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Originally Posted by murphythecat8 View Post
Can you elaborate here? It's really interesting, but I'm really not enough confident or knowledgeable...

What should be the bias results?

its not really the bias, its the input impedence Bias is the cathode resistor's job. most people short sight the importance of the input impedence. I built many tube amps and I noticed comparing my circuits I've tweaked over the years with online schematics the most common mistake is the arbitrary 100k grid to ground on the input tube. There is very few and I will stress there very few designs where 100k of resistance works well and usually they are the buffer circuits (no gain stages) not preamp circuit.

some examples:

with compactatrons, I notice they like somewhere 720k-300k. High gain 12ax7 is more around 270k .
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