Backing out of DIY

[SteveTheShadow]

Yes, the backing out of the DIY stuff continues. The missus didn't think I meant it. She does, however, believe me now.

Having built the twin power supply NVA clone courtesy of Richard's boards a few years ago, I'd also built my Phono 1 into the amp, making it an old school fully functional integrated with phono capability.

Yesterday I was listening to vinyl, via the valve amp and Fane full-rangers when the left channel disappeared. After much cursing, plugging, re-plugging and a process of elimination, the fault was traced to the MoFi StudioPhono itself, which had failed on one channel.
Going inside the thing revealed a board, stuffed with surface mount components. Even the op-amps were surface mount devices, so that was that with regard to repairing the thing.

Back to the NVA clone and despite attenuating the input and, playing with the feedback, the damned thing was still too loud for my 100dB efficient Fanes, but it was the only way now that I was going to be able play any records. I'm not exactly rolling in phono stages.

To cut a long story short, I got completely pissed off with the racket, so decided to look for a pair of speakers more suited to the characteristics of the NVA. Like it or not, the NVA amp is a piss-poor match for big, hi-efficiency speakers. Even Richard acknowledged it. The Fanes go so loud on a mere 1deg turn of the volume control that the amp never really gets to warm up. I've never got the heatsinks above stone cold with the Fanes, which to me must be preventing the amp from giving its best performance, given the fact that Richard always emphasised the importance of a warmed through amplifier.

Anyhow, our Ant came up with a pair of little 1996 vintage Mission 731i speakers that had been stored for ten years at his place. He'd completely forgotten how he had acquired them and they were frankly in a filthy state, but I took them off his hands, brought them home and set about them with soft bristled brush for the bass driver and a tin of Pledge for the case.

They cleaned up a treat and worked when plugged in, after a test for shorts across the input terminals gave the same DC resistance on each speaker. They were advertised as 89dB efficient but are actually around 86dB/W and the attenuated NVA had to be wound to 2 o'clock on the volume control for decent volume. The attenuators were removed, restoring the amp to factory spec.

I must say, with the NVA driving them, they are brilliant little speakers, especially for nowt. I love them. So does the NVA.

731i_in_situ.jpeg (87.71 KiB) Viewed 2154 times

Miss731i.jpeg (63.49 KiB) Viewed 2154 times

The Fanes will be officially retired once I have made some stands for the Missions at the weekend.
Now the heatsinks get warm and the NVA clone sounds better than I have ever heard it. A good result all round I'd say.

[TheMadMick]

I have to say, I've always liked Mission Speakers having bought pairs for each of my offspring. But I only have an old pair of y70's which are far from the top of the Mission speaker tree for myself. Silly me!

[Lindsayt]

I think it's an overstatement to say that NVA amplifiers are a piss poor match for high efficiency speakers.

The amplifiers that I prefer with my 96 and 102 db efficient speakers are a Coincident Frankenstein prototype 300b SET and a Korneff clone 45 SET. If I owned a well executed DIY SET amp, there's a high chance I'd prefer that with my high efficiency speakers to NVA.

However the Coincident and the Korneff are considerably more expensive, new and 2nd hand, than my NVA A20.
Diminishing returns - even with high efficiency speakers - kick in at the NVA A20.
It's one of those where my £133 NVA A20 is a highly cost effective combination with my £485ish EV Sentry III's.

Your Fanes are grin inducingly cost effective speakers.
The Missions even more so, as they were free.

[SteveTheShadow]

There's more to life than hifi. Nobody should feel ashamed about what equipment they use to enjoy their music. One of the reasons I am avoiding forums from now on is the way people make me feel insecure about my choices (my fault).

Anyway, good for you Steve. I have never heard your valve amplifiers or Fane speakers but I am sure they are jolly good. I bet the NVA and Mission are jolly good too. I am enjoying not thinking about diy. Tye constant "what if I just do this.....". It's a never ending cycle that in my case leads to nothing getting finished.

Enjoy your diy free music appreciation

[SteveTheShadow]

….Enjoy your diy free music appreciation

Funny you should say that Stu. Me and the missus were listening to a 70s disco compilation through the NVA/Mission combo this afternoon and ended up in an orgy of granny/grandad dancing around the living room, clapping on the one and three…the pet hate of all the drummers I know.

The system has become a 24 carat groove machine. Neither of us can stop grinning. That’s what it’s all about…the music.

[SteveTheShadow]

….Enjoy your diy free music appreciation

Funny you should say that Stu. Me and the missus were listening to a 70s disco compilation through the NVA/Mission combo this afternoon and ended up in an orgy of granny/grandad dancing around the living room, clapping on the one and three…the pet hate of all the drummers I know.

The system has become a 24 carat groove machine. Neither of us can stop grinning. That’s what it’s all about…the music.

Love a bit of 70's disco, early 80's even. Yes it's all about the music not how many inches your bass driver has got or how expensive your drivers were. I couldn't give a fook about street cred and what other people think about what I am using to listen to music anymore. Oh it's not high sensitivity, your power amps are too under powered, measured distortion is too high blah blah fooking blah. It's us as individuals that listen to the equipment we have assembled and we should feel at ease listening to it. That is why I think looking at hifi forums is of no use what so ever.

Steve, if you want to clap where the bass drum usually plays then that's fine by me. It does'nt have to be on 2 and 4. Hey wait a minute, where you gonna clap on something in 6/8, 3/4 or something by frank zappa ?

[antonio66]

Well done Ant in saving the day with an elderly pair of Mission's, pleased you're enjoying the pairing, great job in cleaning them up as well.

[Vinyl-ant]

I cant remember where those speakers came from, when or why i bought them, or how much they were
Only reason i even remembered them is because id been in that cupboard recently
Interestingly i found a centre speaker from that same range in a different cupboard yesterday afternoon. Must have bought it at the same time but christ knows why

And some faital drivers and sb acoustics tweeters from some other speakers in a box. And a big bag of various cables

The amount of things and stuff i keep finding recently is abit silly, i should really inventory it all, fix what needs fixing and sell some of it off.
I must have at least 20 headshells which i dont really need, there are 7 or 8 arms, probably 10 turntables, at least 5 amps, 2 or 3 cd players, a tape deck somewhere, probably at least 10 cartridges.

Id probably only end up buying even more though to replenish my stock of stuff and things...

[antonio66]

If you sell some of the stuff you don't need now what does it matter, if in a couple of years down the line you have to purchase one of the bits you sold.

[SteveTheShadow]

Well three days into life with the Missions and the treble has come out beautifully. The speakers were a little rolled off last Thursday, but now they are nicely balanced, with no sibilance or harshness anywhere in the upper-mid/treble area.
I found this phenomenon interesting so removing the tweeter, so I could see the crossover, I found a simple first order job, with an inductor on the bass driver and a cap plus padding resistor on the tweeter.

The tweeter cap is a 4.7uF Tesla electrolytic, so that explains why the treble extension improved over time. The cap, not having been used in years will have taken time to re-form. There may be a bit more treble improvement to come, but they are sounding pretty damn’ good whatever.

There could be an argument for replacing the tweeter cap with a higher quality film/foil item, but why mess about? That way lies madness. Too many different makes of cap.

The NVA/Mission combination sounds excellent. The amp, now it is playing into more suitable speakers, is doing nothing wrong at all and seems to be providing fatigue free musical enjoyment, completely different to the Naim amp I had, twenty years ago.

Haven’t stopped grinning for two days.