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[Mr Skrunts]

There was a rather poor wiring job on a Senator which a certain (overly mothered) forum member turned up with to one of our meets!



Sadly I cant find the pic but, it involved the above car with a set of crocodile clips directly onto the battery (no fuse), the wire ran up the bonnet edge and in through the door jam !

Dunno if its ,e or not, but the link came up as passworded.as if the same as the forum I couldnt access it.

[Christian]

Yes i have signed up on AV Forums.

I have a pair of 1972 Goodmand Magnums, there 7ohms each unit and are very sensative.

With just 50 wrms input im looking at around 30wrms to50 wrms a ch!

[Kevin Wood]

Yes i have signed up on AV Forums.

I have a pair of 1972 Goodmand Magnums, there 7ohms each unit and are very sensative.

With just 50 wrms input im looking at around 30wrms to50 wrms a ch!

Well, a push-pull pair of EL34 / KT66 / KT88 / 6550 / 6CA7's will get you into the bottom end of that power range.

Where are you located? If you're anywhere near me we could always see how they sound driven by my amps?

Kevin

[Christian]

Im in telford and never have a weekend of as working  lol

Thats very good of you to offer tho!

Will look up those model codes thanks  

[Marks DTM Calib]

Any valve amp kit will be pricey now, the output transfomrers alone will see little change from 100 quid for a pair, then there is the mains transformers, caps and the bottles them selves.

Hence the chioce of Valve preamp and good Mosfet output stage!

[Christian]

I doubt My Pioneers will make a good output stage over Valve Pre Amping ?

[Marks DTM Calib]

I doubt My Pioneers will make a good output stage over Valve Pre Amping ?

Correct, they were fairly average in thier day in reality.

But, its much cheaper to put together a good Mosfet output stage and use a single or double valve pre-amp setup to get the distortion valve sound you seek.

[Christian]

I doubt My Pioneers will make a good output stage over Valve Pre Amping ?

Correct, they were fairly average in thier day in reality.

But, its much cheaper to put together a good Mosfet output stage and use a single or double valve pre-amp setup to get the distortion valve sound you seek.

The clip is more a natural sound so i recall?

A nicer sounding Harmonic rather than a nasty square wave on a Scope!

[Marks DTM Calib]

I doubt My Pioneers will make a good output stage over Valve Pre Amping ?

Correct, they were fairly average in thier day in reality.

But, its much cheaper to put together a good Mosfet output stage and use a single or double valve pre-amp setup to get the distortion valve sound you seek.

The clip is more a natural sound so i recall?

A nicer sounding Harmonic rather than a nasty square wave on a Scope!

Yep....they 'softly' distort where as a transistor (bipolar or Mosfet) when saturated simply connects the DC rail directly to the output for the short period of clipping.

If you ever did any fourier analysis (a nasty bit of integrtion by parts required), you will under stand how all waveforms are in reality the sum of many sine waves.....and hence under clipping you get 3rd, 5th, 7th.....etc harmonics produced!.

Valves however, distort when not clipping....its the distortion that makes them sound 'soft'.

So, if you want true to life and faithful reproduction of what was recored then its a top notch Mosfet amp and a Cd player.....but many people cant live with a 'pure' sound.

And many main street amps are tuned to a persons ears....e.g. Technics has base boost as standard to give a low down characteristic and Sony even tune thier QS amps to suit a UK 'ear'!....

[Martin_1962]

I doubt My Pioneers will make a good output stage over Valve Pre Amping ?

Correct, they were fairly average in thier day in reality.

But, its much cheaper to put together a good Mosfet output stage and use a single or double valve pre-amp setup to get the distortion valve sound you seek.

The clip is more a natural sound so i recall?

A nicer sounding Harmonic rather than a nasty square wave on a Scope!

Yep....they 'softly' distort where as a transistor (bipolar or Mosfet) when saturated simply connects the DC rail directly to the output for the short period of clipping.

If you ever did any fourier analysis (a nasty bit of integrtion by parts required), you will under stand how all waveforms are in reality the sum of many sine waves.....and hence under clipping you get 3rd, 5th, 7th.....etc harmonics produced!.

Valves however, distort when not clipping....its the distortion that makes them sound 'soft'.

So, if you want true to life and faithful reproduction of what was recored then its a top notch Mosfet amp and a Cd player.....but many people cant live with a 'pure' sound.

And many main street amps are tuned to a persons ears....e.g. Technics has base boost as standard to give a low down characteristic and Sony even tune thier QS amps to suit a UK 'ear'!....

CD Heard enough higher spec stuff to realise that CD is limited and that the two super formats were audably better, and I would go as far to say that DVD-A was slightly better than SACD.

A good DVD-A sounds like you are there

[Christian]

Im really after a more natural sound stage, live a live band playing infront of me !

Now while we are on subject theres somthing i need to get clear Mark.....

A valve Amp only produces a possitive push does it not? and when required a transistor negativally pulls back the wave to make a full wave from Polarity to Polarity?

Or is there just two Valves per push and pull?

Im sure some have a Transistor for negative pulling, where have i read this  :-/

Or is this somthing ive mixed up? or is this another kind of Valve Amp?

[Marks DTM Calib]

The push-pull output stages are different to that of a standard transistor based output.....they rely and driving current in opposing direction through a transformer i.e.:

[Kevin Wood]

A valve Amp only produces a possitive push does it not? and when required a transistor negativally pulls back the wave to make a full wave from Polarity to Polarity?

Or is there just two Valves per push and pull?

Im sure some have a Transistor for negative pulling, where have i read this

I think what you're getting at is that transistors come in both polarities - NPN and PNP in the bipolar world, and often (but not always) the  devices in a transistor output stage will be a "complimentary pair" - an NPN transistor feeding current into the positive half of the cycle and a PNP sinking current to a neghative supply rail during the negative half.

Valves have no equivalent to the PNP device so, in Mark's example above, both halves of the push pull arrangement are drawing current from a positive supply rail. The transformer inverts the output of one of the valves to form the "negative half" of the cycle.

Kevin

[Marks DTM Calib]

A good transistor amp actually uses a quasi-complimentary output stage to get better matching.

[Christian]

Yes that helps see clearer!

Thanks.

I was recomended this as a start, although i got it offered at the price of 500 pounds.

http://www.iconaudio.com/la4.html

How would you rate these products?