Hi guys,
I like the Quad 50 because it is a "tube amp with transistors".
Schematic:
Quad 50E circuit diagram - large copy
Anyone who has a clue about the OPT? I have some biggish 5,5 CT :1 toroids and I wonder if they are suitable for something like this.
Steven
I like the Quad 50 because it is a "tube amp with transistors".
Schematic:
Quad 50E circuit diagram - large copy
Anyone who has a clue about the OPT? I have some biggish 5,5 CT :1 toroids and I wonder if they are suitable for something like this.
Steven
In most valve amps the OPT is a necessary evil, responsible for some of the weaknesses of valve amps. It seems bonkers to add an OPT where it is not needed - or was it just a silly fashion statement? The result is an amplifier which suffers from both valve and SS weaknesses.
A 50E is a Quad 303. As I recall, the 50E has transformer output taps to run it with distributed sound systems...i.e. 70 Volt systems for public address.
Get a 303 off of eBay or build a clone. Great little amp!
Get a 303 off of eBay or build a clone. Great little amp!
That last statement is not always true.
The Q50E was made to specification for the broadcast industry. A 303 with one channel removed and an isolation/output transformer installed. I've not heard a Quad 50E but reports from those that have say it is not as good as the 303 of which i have owned many (close to 20?). Last time i had a 303 i compared it to an Audio Sector chipamp. The 303 was embarrased. I have since given up on 303s.
Rene Jaeger brought a couple high voltage (300-350V) MOSFET power amplifiers with DHT driver stages and output transformers to VI diyFEST a couple years ago that exhibited fantastic performance.
dave
Peter Walker design, with redo (after 50% field failures) by Peter Baxandall. Not likely to be a fashion statement.
I must disagree with the statement that the 50 is similar to the 303. The transformer may be configured for various output impedances, but that is not its main function. It is a push-pull design with 2 identical output devices, like your average EL34 amp.
The 303 has quasi-complementary outputs which makes it a totally different design. Probably they couldn't make good power PNP's back then.
The 303 has quasi-complementary outputs which makes it a totally different design. Probably they couldn't make good power PNP's back then.
I am a DIYer of tube amplifiers. Recently, I have few Quad 50E for repair and restoration. After all the works had been done, I found that this amp sounds so sweet like tube amps. Also, it has very low distortion of less and 0.1% below 2 watts and 0.2% from 2 to almost full power 50 watts rms.
Wonderful sounding amplifier that I would say this is the best solid-state amplifier that I have ever heard.
Wonderful sounding amplifier that I would say this is the best solid-state amplifier that I have ever heard.
Dis they come from the CBC? I talked with some engineers there and they didnot think the amp that good.
I have yet to hear one. Certainly the Quad 303 it is based on has not aged well. I still love the cosmetics.
dave
According to the seller, they all came from CBC studio.
If you like the sound of the tube amplifiers, surely you would like this Quad 50E.
If you like the sound of the tube amplifiers, surely you would like this Quad 50E.
It is not based on the 303. It came before. If anything it is the other way around, but as pointed out above they are very different beasts.