Nu-Vista pre amp and power supply

[nando]

I'm looking forward to the kit, with the ohmite resistor!

Have you made a schematic of some x-serie apparatus? Or do you just look at the pcb and see that the 4 resistors are connected in series and can be replaced by one?

[nando]

ARRRGGGGGGG

&%@^#(#!%&(#@!%@#

*#%&@#(^%$@#)


I have been spending several hours searching and comparing components on the Dutch version of RS-online webshop.... But they need a kvk number from me so you need a Dutch company to order parts.

[PinkFloyd]

I've got an account with RS so if you send me the part numbers and quantity you require I will order them from RS UK...... no probs at all..... and get them to ship to your address

RS are a bit expensive these days so I've been using Mouser and it's a fair bit cheaper to buy from the USA..... how daft is that?

I enjoy the parts hunt Nando so don't stress out..... just let me know the RS part numbers and I'll order them for you.

The problem with buying one or two items is that you don't get a price break so I always tend to go "large" and order in 500 +

There's a very small company that operate out of a garden shed Nando..... they are excellent for certain items but best to get them to send you a catalogue as their online shop is SHIT! 6 times more in the catalogue than in their online shop and they are mostly cheaper than RS.

Have been parts hunting for 25 years so pretty much know all the angles........ 1 hour searching for a part that I had in the workshop was really good fun. I have four of them and was like "WTF are these things?!" after a lot of Google image searches they could only be ONE thing........... an ALPS - EC11B152442D - ENCODER, ROTARY, 11MM, SWITCH, 15PPR, with pushbutton!!

Took me an hour to do a bit of detective work and am glad to know that I am the proud owner of 4 x EC11B152442D - ENCODER, ROTARY, 11MM, SWITCH, 15PPR, with pushbutton...... erm? what?!! I didn't even know that such a thing a thing existed and quite why FOUR of them were in a tray in the workshop God only knows

Anyhoo...... I have put them on Ebay so fellow encoder lovers can marvel in the four EC11B152442D with pushbuttons I now have for sale. I have always said "It's not an EC11B152442D unless it has a pushbutton"........ erm, still no idea of how I own 4 brand new ones but happy that I now know what the f**k they are

I've put them on ebay at a bargain price of £5 so all the millions of "EC11B152442D with pushbutton" fans will go in hard on that one. www.ebay.co.uk/itm/172809667088?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Not really worth the time spent finding out what they were but it's what I like to do. A fiver these days is a handful of peanuts.

Oh well...... hopefully somebody will be happy with an EC11B152442D (with pushbutton) for a fiver

[PinkFloyd]

A Pushbutton peanut dispenser....... Now that's something I would bid on....

[nando]

HAHA, that's funny. Form an "ALPS - EC11B152442D - ENCODER, ROTARY, 11MM, SWITCH, 15PPR, with pushbutton" fanclub!

I'll join.

Monty Python for real.

[nando]

What a puzzle from hell was that... Nice list of things from RS but not able to order there. A list with elco capacitors for nu-vista, x24k, xtone and xlp at the same time. Some capacitors could be the same with different cans.
Then converting the list in excel sheet and importing in website of Mouser. Several items were not available or not recognised so trying to sort that out. And then now here I am a couple of hours forward in time *poof*.

Hopefully the delivery is before the weekend so I can begin soldering together with my father. Hoping the parts don't blow up in our faces.

I chose for Panasonic FR if possible. If not then Panasonic FC, if nog then NHG. In one case MF placed a 105C capacitor so I thought I can outclass this with a 135C Panasonic TP series capacitor.
In some cases I could not get any Panasonic so converted to Nichicon.
In all cases I chose the 105C versions for some added durability.


If all goes as planned....
The Nu-Vista power section will go from 4x1000uF + 4x2200uF = 12.800uF
to 4x1200uF + 4x5600uF = 27.200uF

The x-24k power section will go from 2x2200uF + 4x1000uF = 8400uF
to 2x3300uF + 4x2700 = 17.400uF

The x-tone power section will go from 2x100uF + 4x1000uF = 4200uF
to 6x2200 = 13.200uF

The x-lp power section will go from 2x100uF + 4x1000uF = 4200uF
to 6x2200 = 13.200uF

[PinkFloyd]

That should be you sorted Nando I tend to use the Panasonic NHG 3300uF in place of the 2200uF because they are a good size / same package size as the 2200uF. Not to keen on shoehorning larger capacitors in, it just doesn't look right to my eyes.

All the work you're doing should preserve your gear for at least another 20 years AND make it sound better! Hope all goes well, have fun

[nando]

It's not even an educated guess because i'm not educated (in this kind of physics anyway).

So trail and hopefully not to many error. I'll keek you posterd on the progress.

[PinkFloyd]

Aug 8, 2017 20:28:21 GMT nando said:

It's not even an educated guess because i'm not educated (in this kind of physics anyway).

So trail and hopefully not to many error. I'll keek you posterd on the progress.

You're a lot more educated than you think......

You're a damned cool geezer.........

You can't get cooler than cool so consider yourself cool Nando!

Seriously, you're cool AND educated...... never doubt yourself mate.

Best regards,

Mike.

[nando]

Aug 8, 2017 9:40:04 GMT PinkFloyd said:

That should be you sorted Nando I tend to use the Panasonic NHG 3300uF in place of the 2200uF because they are a good size / same package size as the 2200uF. Not to keen on shoehorning larger capacitors in, it just doesn't look right to my eyes.

All the work you're doing should preserve your gear for at least another 20 years AND make it sound better! Hope all goes well, have fun

I tried to look at capacitence, lifetime, max temperature but also measured the space where it has to go (diameter and height). The last is a bit of a guess because I don't have a lot of experience with it. I may have overcooked it with my parts choice but we will find out soon enough.

Last moment before placing the order for parts, I read about esr and ripple currect. I got a bit nervous because I didn't totally understand and may be buying some incompatible parts. I'm not a novice in reading English but this was quite a challenge because of the technical language.
As I understand esr is the resistence a (capacitor) has in the circuit. Is the esr low then the current will be high with heat as a result. As I thing of it, it might be the other way around... argh, I don't understand enough yet.
The ripple current is the maximum current a capacitor is able to flatten from dc to ac.
Am I close?

[PinkFloyd]

Don't worry..... all of the capacitors you have chosen will be perfectly good in the equipment you are using them in. As a "simple" rule of thumb a higher ripple rating than the original capacitor is fine but a lower one may not be.

2200uF Jamicon SK 35V / 2200uF = 1650mA

2200uF Panasonic FC 35V / 2200uF = 3010mA

3300uF Panasonic FC 35V / 3300uF = 3680mA

Some manufacturers measure @ 120kHz and others @ 100kHz so it can seem confusing but all you need to know is that the caps you have selected are absolutely PERFECT for the intended application and far exceed the specs of the original SK caps in every single respect.

FR is a very good capacitor.... doesn't "look" good (grey and black) but it delivers both in lifespan and sound quality..... FM is one of my all-time audio favourites, 7,000 hours @105c (real lifespan in an X-CAN probably >30 years PLUS!)... they are good quality caps.....

Don't stress out over ripple current Mate.... every single cap you are employing in place of the Jamicon SK is a lot better specced! (and I mean a LOT!)

Far superior with regard to longevity and sound quality...... just what the Doctor ordered.

A few Simple rules:

Stick to the same voltage rated cap OR go higher / never use a lower voltage rated cap.

Go for a higher ripple current (mA) capacitor but not a lower one.

In your particular applications choose a low ESR capacitor..... the lower the better.

In the PSU section try to get more juice on tap (ie: replace 1000uF with 3300uF etc.)

There are variations to the rule such as not employing low ESR caps after the regulators (linear PSU) but even those can be broken..... it all depends on the circuit and this is where experience dictates what sounds best Low ESR are your friend in a switched mode (SMPS).... argh! I'm starting to get vertigo and about to fall off my chair with all this "datasheet" stuff.... it's about as confusing as choosing a mobile phone

Best regards,

Mike.

[PinkFloyd]

I'm sure Pengu will chip in on this one with his views.

[nando]

I sure want to have more knowledge but I'm learning along the way. So in a few years I will what I should have done last week.

[nando]

Aug 9, 2017 20:49:52 GMT PinkFloyd said:

I'm sure Pengu will chip in on this one with his views.

Yes, please!

Is there someting I'm supposed to watch out for (except smoke, fire, elco content flying up my nose).
For instance, is it better to change a elco, connect to power and then check if it works or could I change the lot of them and fire up then?

I have to change four big snap-in capacitors. Any tips?

[nando]

Ready to go!

[PinkFloyd]

Aug 11, 2017 11:27:35 GMT nando said:

Aug 9, 2017 20:49:52 GMT PinkFloyd said:

I'm sure Pengu will chip in on this one with his views.

Yes, please!

Is there someting I'm supposed to watch out for (except smoke, fire, elco content flying up my nose).
For instance, is it better to change a elco, connect to power and then check if it works or could I change the lot of them and fire up then?

Pay attention to each solder join, do a good job and move on to the next one. As long as your desoldering / soldering skills are up to scratch there will be no smoke!

Make sure you put the caps in the right way round + to + / - to - and there will be no problems. The negative side of an electrolytic cap is denoted by the band running down the side of it.... the other way of telling is the longest capacitor leg = positive and the shorter one = negative.

Just concentrate when fitting the caps because if you fit + to - by mistake the cap will get hot and explode....... won't damage anything other than the cap BUT the "bang!" may cause you to shit your pants

You'll be fine

[PinkFloyd]

Aug 11, 2017 19:56:00 GMT nando said:

Ready to go!

Bon Voyage Sir..... looking good

[nando]

Been busy together with my father.

Hand of the master... my father resoldered all of these. It is a switch, and I hope the tuner input will function because of this work (I doubt it but it's worth a shot)


Nichicon 1200uF (replacing 1000uF Jamicon) and at the back a Panasonic FR 5600 uF (replacing 2200 uF Jamicon)


Didn't do myself a favour here. With removing the old capacitor, I almost removed a pcb track as well. The track came loose for a few mm's. The track runs underneath the relais so it's quite unclear where the track runs to and if it's still working. The track was still attached to the pcb under the relais so probably it's still good but we can't see propperly.
We tried to stick the loose track to the tin on the soldering island. Hope it's enough.


Panasonic FC 2200uF (replacing Jamicon 2200uF).

[PinkFloyd]

I'm not a fan of giant blobs of solder Nando and they tend to do nothing other than make a mess. You're better to suck up that blob of solder and see exactly what's going on under it..... simply laying the solder on thick won't fix a problem

Looking good for the rest of it mate..... your Dad is good at soldering

[PinkFloyd]

suck all of the solder up........ scrape back the track until you expose the bare copper and then resolder onto the bare copper...... the "blob" is not the best way to do it

[nando]

What we are afraid of is that I tore the whole copper track of the pcb so there is nothing to scrape towards. The relais is on top of the track and annoyingly blocks the vision. We couldn't find (multimeter) a connection to one of the soldering points of the relais so we trought it runs under the relais to somewhere else on the pcb. If the relais was easy to desolder we would've but my father said that if we try that we might as well order a new relais because we will break it.

[nando]

The Nu Vista is done.

Here are some photo's.






This is underneath the power supply board. I fitted heatsinks to the transistors.




I was very careful in placing the heatsinks so they don't touch metal leads of other components.




Had to bend and break some pieces of the heatsinks in order to clear them from other metal parts.











Amp with the power supply board and ready for reassembly in the casing.

[nando]

What I did:

Replace all electrolytic caps for Panasonic FR, FM or Nichicon (bipolar ones).
Replace the valves with Westinghouse ones.
Replace stock diodes with UF4007.
Replaced 4 pin RCA connector with a new one.
Placed 9 heatsinks on most transistors on the bottom board. Those that were running hot.
Replaced four filmcaps for EVOX filmcaps.
Resoldered all the solderjoints.

Result is that the amp still works (pffieuw) and the non functioning tuner input works again.
Oh, and a bonus is that I learned a hell of a lot in the proces. This was a project started quite some time ago and I would have done a few things different if I was to do it again. But there are no big mistakes as far as I can see.

Haven't had a critical listen. That's for a later moment.

[nando]

There is more work to ve done on the nu-vista pre amp. I hoped the input selector would be fine after a resolder an cleaning of the pcb but no... it’s getting worse by the week so it seems. Now the music signal is getting destorted while playing and mono often. When I move the knob a little within the tollerence of the selected input, the music crackles and goes mono as well.

I guess it needs a cleaning but the problem is that the selector unit is encaged. Desoldering and replacing is another option but them I have to find the part and it has a lot of solderpoints.

[nando]

How do I know what part the input selector is in this Nu-Vista?
It's a motorised alps as seen on the last posted photo above. It has hardly any markings on it.
The case says no more than "ALPS JAPAN". That's not enough to order on Mouser...

Is there an other way than desolder the bugger and hope there is some type number under the alu case?