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Re: chips and tubes [message #10248 is a reply to message #10244] Tue, 07 December 2004 16:01 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18675
Registered: January 2001
Illuminati (33rd Degree)
Could be anything. Could be the amp topology. Maybe the substrate. Might be the surrounding components. Might even be the music or the moods.

When you compare 'em, please let us know.

I remember the Yamaha receiver in the 1980's sounded really great. I was impressed with it in several ways. I don't know how it compares with some of the gear I have now, but it sure made an impression on me an many others that heard it. I ran it on seven π Speakers with all JBL Professional Series drivers.

To tell the truth, the inexpensive Harman Kardon HK 3470 receiver I picked up on Crutchfield a year ago sounds pretty good. I bought it to see how an entry level home theater would sound with two π's and tower two π's. I wanted solid state with about 100 watts per channel for this particular setup. That way I could compare tubes and solid state in the price range that most would probably use with one π's and two π's. I've never opened it to see if it uses a chip amp or discrete components, but more than likely, it's a chip. Maybe a National chip, just like the gainclones. I dunno. But it sounds pretty good; Suprising, really.

Wayne

Re: chips and tubes [message #10249 is a reply to message #10247] Tue, 07 December 2004 16:20 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Well I agree to some extent but the GC sounds pretty good with the Foreplay as a pre-amp. I would put the sound ahead of the usual recievers.

Re: chips and tubes [message #10251 is a reply to message #10249] Tue, 07 December 2004 17:14 Go to previous messageGo to next message
hitsware is currently offline  hitsware
Messages: 51
Registered: May 2009
Baron
Is the Foreplay a tube unit ?

Re: chips and tubes [message #10252 is a reply to message #10251] Tue, 07 December 2004 18:40 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Yes Bottlehead makes it. 12au7 tubes.

Re: chips and tubes [message #10253 is a reply to message #10252] Wed, 08 December 2004 07:48 Go to previous messageGo to next message
hitsware is currently offline  hitsware
Messages: 51
Registered: May 2009
Baron
Yea. Here they have a thread about using a tube follower as a buffer to drive an inverting gainclone. Adds the 'tube magic' I guess. If I was going to use a tube though, I'd use it for the voltage gain and simply add a complimentary mosfet follower. 0 global feedback (which (to me)) makes for Mr. Groovysound.......mike

Re: chips and tubes [message #10254 is a reply to message #10253] Wed, 08 December 2004 18:33 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
I have not heard the buffered GC but I have heard another buffered SS amp. Does'nt make sense to me, Tube Sound is wrong, if your amp has Tube Sound, fix it. I have heard quite a few well designed tube amps and their characteristic sound is one of music. SS amps are too bright and lifeless for me. I do like the chips though; but honestly they too have a little sheen to them. It's just that they are so much fun. Run Mr. Groovysound by me again; have you used this configuration? The tube is a voltage gain stage ahead of the GC?

Re: chips and tubes [message #10255 is a reply to message #10254] Wed, 08 December 2004 19:57 Go to previous messageGo to next message
hitsware is currently offline  hitsware
Messages: 51
Registered: May 2009
Baron

I haven't used a tube but do use a mosfet. A tube could be substituted for the 1rst xsistor......NO global feedback. Impossible with a power op amp...........mike

Re: chips and tubes [message #10257 is a reply to message #10255] Thu, 09 December 2004 11:39 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
mike; I know op-amps use sometimes 100db of Global Feedback. But I was under the impression that GC's use some amount of GF also. Is that incorrect?

Re: reposting schematic [message #10258 is a reply to message #10255] Thu, 09 December 2004 16:19 Go to previous messageGo to next message
hitsware is currently offline  hitsware
Messages: 51
Registered: May 2009
Baron

this time with more stable url.......

Re: chips and tubes [message #10259 is a reply to message #10257] Thu, 09 December 2004 16:35 Go to previous messageGo to previous message
hitsware is currently offline  hitsware
Messages: 51
Registered: May 2009
Baron
>I know op-amps use sometimes 100db of Global Feedback.
>But I was under the impression that GC's use some amount
>of GF also. Is that incorrect?

Correctomundo. The chips used for GC's are in fact op-amps.
Perhaps more correctly 'power op-amps'. This is the same
topology used in 99% of solid state amps (only the circuit
is all on 1 'chip'). As much gain as possible is developed,
affording massive feedback for low distortion specs.
In fact so much gain that feedback must be used to define
a reasonable operating condition.
Fine and dandy. Some of them sound great. For my tastes though,
amps with little or no feedback (and here I mean 'global' or
'active' feedback where the output is fed back (as opposed to
'degenerative' that simply limits the gain of a device)) have
a truly more groovy sound. WAY more dynamic and open .... mike


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