Rectifier used in HMV 2022 Record Player.

[Old Sparky]

This afternoon, I fitted an ECL86 borrowed from my Revelation Silvertone record player, so I now know the one I originally fitted was fault, as I ran the HMV player for maybe 3 hours continuously, playing both sides of 5 different LPs continuously, some of the time at quite high volume. I also measured with my M-3800 DMM, the o/p from the cartridge, which peaked at 500-600mV on highly modulated passages of said records, so my conclusion is that, as far as the 2022 goes 'this is as good as it gets!' Now to source a reasonably priced NOS ECL86 if there is such a thing!

[Murphyv310]

Pm me your address and I'll send you one FOC.

[Mark Hennessy]

Well that's rather confusing given the report in post #29, but at least we're getting there

[Old Sparky]

The test I described in #29 was carried out withe the amp. on the bench, and without the cartridge connected, and, if I measured the o/p power level at that time I didn't make a note of it. This afternoon, with a known good ECL86 fitted, and as I noted in post # 61, I measured the signal level across the pickup's o/p at the point wher the screened cable connects to the amp's i/p, with an LP playing. I may repeat the test tomorrow with an o/p meter and external speaker, as well as using my 'HiFi for Pleasure' Test Record, which has various tones recorded on it, but all in all the player works as well as this kind of set ever does. Given the readings I obtained when playing an LP, I'd imagine that a 45rpm single would produce a higher output, maybe up to the quoted 1000mV level.

[Mark Hennessy]

Certainly, there was a lack of precision in post #29, which is why I used the word "suggests" in post #42. Given that this is a technical forum, it would be really nice if folk were more precise in situations like this, as it would save a lot of speculation and going round in circles.

Looking again, you said ~100mV gave a "healthy" output. Now, given that that's 20dB less than 1V, then I don't feel the need for apologising for the conclusion I reached.

Actually, for my own education, I'd like to know the difference in gain from the two valves, and I'd like to know the DC conditions of each. In my limited experience of the ECL86, providing the DC conditions are about right, the AC gain seems to be good in all cases. Only when they are really off do we see weak gain.

In threads like this in future, I might intervene sooner to get actual data rather than anecdote. It makes a massive difference.

[Old Sparky]

Apologies for my lack of precision in post #29, Mark. I admit to not always making notes of voltage readingss, power outputs, and other data. Back when I did the test mentioned in post #29, I simply wanted to se how the amp. performed with a sinewave signal at an approximately known level - i say approximately because my Audio Generator doesn't have a calibrated fine level control. The 'corase control can be switched to give maximum o/ps of 20, 200, & 2000mV respectively, whilst the 'fine' control ( a liniear pot.) varies that, and, at half max. setting on the 200mV range, approx. 100mV is produvced. Going back to the record player, I haven't noted the gain figures between the two valves, either, being content to know that the replacemnet one provides good quality sound at all settings of the player's controls, whilst the first one distorts after ca. 20 minutes, no doubt due to Heater-Cathode leakage. After over 44 years in the repair business I don't write up everything the way I did back in the 60s & 70s!

[Old Sparky]

This afternoon, I carried out further tests, firstly with a stack of 45s, then with my test record. In both cases I measured the o/p from the pickup at the amp's i/p, getting variable readings of up to and over 1v with music discs, and steady readings of 1v or more from the tones on the test record. I didn't , however measure the o/p power, but there is plenty of volume available, so i consider this, at last, a finished job.

[Murphyv310]

Hi.
Do you not want the NOS ECL86 I offered you?

[Old Sparky]

Sorry, Trevor. Somehow I missed your offer. I'd be grateful for the Valve if you still have it. I'll PM you my address shortly.

[Murphyv310]

Hi.
I've got your PM. I'll parcel it up today and post it tomorrow for you.