audio-talk

Is anyone interested in a nice and easy renovation project before I put on slease-bay? Overall good condition although the alu suspension parts would be nice polished up. No tonearm. Seems to run fine with 240V applied. One owner from new. Comes with original box but I wouldn't want to post. Collect...

Well after getting an underslung Iceni counterweight for my RB250, I have no problem with bass, if anything it's too strong, (or I'm just not used to it). So is it worth trying the Mayware against the Rega? Is it a case of being different rather than better? Also did a little reading on the AT30C an...

Well being a good neighbour in these hard times pays off. Looks like my windfall includes: Ariston RD40 Mayware Formula IV AT30E AT630SUT Plus around 25 albums including Floyd, Queen, Joe Jackson, Dire Straits, Santana, Brubeck etc but unsure of condition. Ariston Mayware AT (4).jpg So what to do? T...

pre65 wrote: ↑Mon Feb 24, 2020 11:23 am Repeat CD plays ? Phono stage ?

I did something similar using an inverse RIAA card and a potentiometer

Are these an option - used in my Niobium: http://vinylsavor.blogspot.com/2012/01/ ... -6by5.html

You beat me to it. Would be interested in the spindle and how it connects to the gearbox shaft. Also you seem to have a solution to the record clamp.

Looks very good and hopefully you are impressed with the results.

So finally in a position to box this up tomorrow after doing a lot more than I had envisaged or planned. Learnt a lot and found three faults with the amp: As we know, voltage regulator not working (original builder's fault) Channels swapped over at the line stage (original builder's fault) Incorrect...

So a bit of tinkering and the inverse RIAA is sort of working. Initially there was a bit of 'undershoot so have reduced the series RIAA resistor from the theoretical 284k to 269k, resulting in: Inverse RIAA 269k small.jpg My question is how much more can this be improved, is this reasonable, and I g...

Am I right in assuming you test the valve with 2 different bias conditions and then calculate gm by (Ia1-Ia2)/(Vg1-Vg2)?

Has anyone made one that could be used to measure/calculate gm and Ia?

What about the attached? https://www.valveheaven.com/wp-content/ ... tester.pdf

So getting psyched up for trying to do a square wave test. Trying out my cheap Chinese signal generator and oscilloscope. Is the attached image showing a good enough waveform to do this test, shown at 950Hz? Square Wave Small (2).jpg The Inverse RIAA card has a selector switch for -40 and -60dB, so ...

I'm inclined to remove them if not fully justified in my quest for simplification.

As per the original amplifier stage design, although perhaps well intended, they seem excessive and less may hopefully be more!

Why might the designer have added the 100k and 220k resistors to the cathodes of the bottom and top triodes in the regulator?

Looking at my Rozenblit book, with a single triode regulator, there is no resistor from the ECC83 cathode to the regulated output.

Well spotted Mike. I couldn't understand why the EL84 Vg was so large when looking at it's triode characteristics, should have been a volt of so at the most for Va 100V and 35mA. Left the load at 470k (as per a Rozenblit circuit) and I think all is OK now with voltages as attachment :D . 41V across ...

Will do. From what Nick said about my proposed pentode design, the load resistor should come off the anode side of the EL84 anyway, so probably an improvement over the originators design. Just a bugger to do. Running short term with the pre-amp ECC82s removed to limit the load. Sounds great this aft...