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Courtiestown - Naim Amplifier (Avondale) Upgrade Project

Good Morning All,

I'll be glad to get back home circa the 14th, it seems like I've been away for ever on this last job (it does pay the bills though).

I've sent a PM to @chiily of this parish as he has previously indicated having spare PTH Quasimodo PCB's and I made contact with somebody on diyaudio (US based) who was providing kits and am waiting on cost including P&P.

Regards

Richard
 
I Quasi'd my entire system and after a while wondered why I didn't like listening to it anymore. I then removed them one by one and each time the sound became more appealing. Maybe I like the sound of additional noise, or maybe the snubbing methodology is not ideal? I did wonder if snubbing an unloaded transformer results in component values that don't work well when the transformer is loaded.
Whatever: if it sounds worse, it is worse! ;)
 
Whatever: if it sounds worse, it is worse! ;)

Interesting. Yours is not the first query/ observation as to whether this snubbing needs to be done under load. How would you achieve this in the real world or do you need to make a determination as to what the load is and attach a 'dummy' to the secondary?

There are a whole host of modifications I would love to try out on the various PCB's. I'm accumulating the wherewithal to do so but finding the time is a whole different ball game......

Regards

Richard
 
Interesting. Yours is not the first query/ observation as to whether this snubbing needs to be done under load. How would you achieve this in the real world or do you need to make a determination as to what the load is and attach a 'dummy' to the secondary?

It's hard to see how this could be achieved, as the load varies with the musical signal.
 
Good Afternoon All,

Continuing to make as much progress as I can being this far from home so that I can get on with things when I do get home.

Had Kate dig these out to confirm numbers:-

UKGIuml.jpg


6 required - check

Various components ordered to assemble these so orders out to Mouser/ Farnell and eBay:-

SSBx47T.jpg


and if I go down the Quasimodo route:-

ze6ZBKu.jpg


Next up will be ordering some ModuShop cases when the summer offer starts tomorrow.

Regards

Richard
 
Funnily enough my missus suffers the same: kitchenalia and electronics. :D
Don't get the methylated spirits mixed up with the squash or the cooking oil... :confused:;)
Yes more kitchen amps
Good Afternoon All,

They say a little knowledge is a dangerous thing......... so on that basis......

Whilst "reading" Doug Self's "Audio Power Amplifier Design Handbook" I was intrigued to see mention of a 1000uF feedback capacitor.

Acknowledging this as being from said book above:-

RFlJaCM.png


I'm currently at 300uF which seems some way up on LesW's original proposed value of 47uF.

Is this something that needs to be tried?? I was surprised to see the back to back diodes, DS notes that there are four to counter the increase in distortion caused by just the two?

Could somebody explain this in simple terms and also comment on heading upwards from a 300uF capacitor in the feedback position?

Regards

Richard[/QU
Good Afternoon All,

They say a little knowledge is a dangerous thing......... so on that basis......

Whilst "reading" Doug Self's "Audio Power Amplifier Design Handbook" I was intrigued to see mention of a 1000uF feedback capacitor.

Acknowledging this as being from said book above:-

RFlJaCM.png


I'm currently at 300uF which seems some way up on LesW's original proposed value of 47uF.

Is this something that needs to be tried?? I was surprised to see the back to back diodes, DS notes that there are four to counter the increase in distortion caused by just the two?

Could somebody explain this in simple terms and also comment on heading upwards from a 300uF capacitor in the feedback position?

Regards

Richard

Good day if you build NAP140 amplifier you no need use the feedback caps more 100uf
because if you use 150uf or 220uf or 470uf feedback caps you lost frequency balance in bass register of sound.
For examples please watch of new Naim nait5i schematic and you see 470uf caps in feedback
this is mistake of Naim designers they try correct zero but they not thinking about sound :)))

if designer who create another amp use 470 or 1000uf feedback caps he have mistakes with zero voltage balance in output
If you have that problem with zero in output
better way use opamp or change schematic and make clean any mistakes.
 
Good Evening All,

I'm continuing to accumulate "stuff" to carry on my amplifier upgrades.

The Quasimodo kit has arrived from the US of A:-

8J1OGRU.jpg


and 20off Nichicon KZ 100uF/ 100V to be used in decoupling positions as well as Elna Silmic II and some other Nichicon's so comparisons can be made:-

Iyrmauc.jpg


Regards

Richard
 
Last edited:
@Richard Lines

Sure - but such a thing doesn't link your hobby interests, musical equipment tastes, investments in such directly to a stream of existing info here.

I.e no need to advertise here (or anywhere): while 'we', regular members who converse may all be nice sensible people, you have no control over where that image is spidered by search engines/ scraped/ who sees it/ some dishonourable rogue noticing one might be into nice-to-have things, with an address attached. goes search back on posts 'you' / such a person / has made here for ...interest (as with many forums, the search here works to non-logged-members... the right thing for sharing opinions & values in the generous spirit , yet a two-edged sword)

It's all a hopefully-very-remote possibility, for us all; also a much wider bleak reality that we shouldn't have to think of - yet sadly, must.

ATB

(PS - and apols - yes, I will get to that email reply this weekend; overlapping waves / other fronts, intervened. M)
 
Good Morning All,

Back to making a hi-fi related posting at last.

OK so this is an old HiCap:-

vEnNfT4.jpg


They just don't make Felsic's like that anymore!! I'm going to be putting this inside it:-

tpQXfAV.jpg


I don't know whether this is the standard heat sink as it doesn't seem to lend itself as a direct bolt on replacement?

This will be used to power the NAXO when it finds its way back from Salisbury.

In the meantime I was looking out of the back door having heard some activity and this is what I saw:-

dnOwRaz.jpg


If you look carefully under the roller shutter door you can see a ModuShop box has been delivered - why can't Fedex drivers knock on the door or ring the bell?? There's a lot of stuff out of the shed whilst some determined rat catching is ongoing..........

Meanwhile still more CAP6's under construction:-

EXpeDCJ.jpg


Regards

Richard
 
There is a complete schematic here...

Just when you thought that the light at the end of the tunnel was getting brighter.................. I now need to go and look through the 8 pages of the thread linked.

I'm going to have to put the HackerNap project on the back burner for now as I need to get something completed and functional and the HackerNap needs more time spending on it. The honest truth is I don't know that it would be better than the SE devices coming out of Avondale?

Regards

Richard
 
Just when you thought that the light at the end of the tunnel was getting brighter.................. I now need to go and look through the 8 pages of the thread linked.

Oh, sorry... I thought it might save you some time to see the schematic...

I'm going to have to put the HackerNap project on the back burner for now as I need to get something completed and functional and the HackerNap needs more time spending on it. The honest truth is I don't know that it would be better than the SE devices coming out of Avondale?

I know that many prefer the Avondale boards to an original Naim, but to me it's opposite: the closer to the original the better. I heard a comparison between a Supernait1 and an NCC300 amp, and despite the latter being much more souvereign the SN1 was vastly superior in regard to how it communicates the music to the listener. For example loud and crowded passages were much tidyer than with the NCC, bass lines were easier to follow, the emotional content came through more involving, etc. In other words: the NCC sounded better, but the SN1 made better music.

I cannot speak about the upcoming SE circuits as I never heard them... I would love to hear an amp which can do both of the above, but the only one I remember was a NAP500 (non-DR). Even active 135s (into NBLs) were killed by the passive 500 - but that's only my personal opinion...
 
Oh, sorry... I thought it might save you some time to see the schematic...

Don't misunderstand me but when the HackerNap PCB's arrived through the post from a still unidentified mystery donor I thought it would be a simple build but when I looked into it I discovered that a relatively simple build could become quite complicated and required slightly more "research' than I had originally reckoned on.

In the meantime I'm on with "bodging" the TPR4 as received and the old HiCap regulator. The job was made easier by the TO-3 mounting holes being sleeved so 4 of the 6 TO-220 devices on the TPR4 fitted without any work being required.

jEkJsm1.jpg


Two of the devices required a 3.5mm hole drilling:-

HkP7xgJ.jpg


Finally it is now bolted back in to the HiCap:-

qlERIOE.jpg


I need Kate to help me now by holding on to the six wire ends while I do some soldering as it makes things a lot easier.

Regards

Richard
 


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