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Avondale DIY upgrades for Naim NAP 180 and 250

Start with replacing the boards in your 180 to guage the improvement, then go from there. You can always swap things back, etc.
 
Adding front-end regulation "later" isn't typically an option, as you need a second transformer and Cap6 module, and usually means you're building mono amps or have a very large case. It doesn't apply if you're upgrading Naim boxes.

Thanks for the clarification Mike, I'm confused then, there is a clear photo of the innards of a 180 with two of the minicap modules replacing the original regulator board and a pair of NCC200 modules on the AA Facebook channel, it was in 2016 mind you so it's well old and may not be suitable for the NCC220 boards ?. It's a 180 I am thinking of modifying so it is a full width Naim box right enough.
 
If this can inspire you, below is a picture of a (crazy) guy (not me !) that did put two power supplies c/w transfos inside an Naim NAP 160 bolt down :

 
Thanks for the clarification Mike, I'm confused then, there is a clear photo of the innards of a 180 with two of the minicap modules replacing the original regulator board and a pair of NCC200 modules on the AA Facebook channel, it was in 2016 mind you so it's well old and may not be suitable for the NCC220 boards ?. It's a 180 I am thinking of modifying so it is a full width Naim box right enough.
The cap6 isn't a regulator board, it just replaces the existing rectifier/capacitor pcb in the 180. This is the facebook post you are referring to I think. That's basically just gone dual mono with the power supply.
 
The cap6 isn't a regulator board, it just replaces the existing rectifier/capacitor pcb in the 180. This is the facebook post you are referring to I think. That's basically just gone dual mono with the power supply.

Excuse my ignorance here, is dual mono not stereo ? OK, I know that stereo is not the same information going to each channel but why would anyone want to hear mono these days. If I'm not mistaken the Nap 135s are a mono amp hence the need for two of them in a stereo set-up. It looks as though Les is using NAP180 cases as a donor to create his 180/300 mono amps, but the link you attached (yes it is that one) looks like it has left and right speaker outputs, different to his 180/300s which only have a single pair.
 
Thanks for the clarification Mike, I'm confused then, there is a clear photo of the innards of a 180 with two of the minicap modules replacing the original regulator board and a pair of NCC200 modules on the AA Facebook channel, it was in 2016 mind you so it's well old and may not be suitable for the NCC220 boards ?. It's a 180 I am thinking of modifying so it is a full width Naim box right enough.
I understand your confusion. Perhaps I can help a bit:
  • Naim Audio Power Amp (NAPA) boards require a single power supply. This can come directly from a Transformer, and capacitor bank, or from a regulator board. The NAP180 has a single power supply, which supplies both NAPA boards. (It also includes an additional supply for the pre-amp, for those who don't have a Hi-Cap or equivalent between their pre-amp and power amp.) All that stuff pretty much fills the the space in the NAP180. To upgrade the NAP180 with Avondale boards, you just swap the NAPA boards for NCC200 (good) or NCC220 (better). This is an easy change, with a notable boost in performance.
  • The NAP250 is similar to the NAP180, in that it has a single power supply (transformer and capacitor pair). However, it doesn't include the supply for the pre-amp, which gives it a bit more space to play. They move things around and fit two regulator boards (each roughly equivalent to Avondale's HCR200 module). Both of those regulator boards share the transformer cap-pair supply. Each regulator board supplies one NAPA board within the NAP250. To upgrade the NAP250, you can swap the NAPA boards for NCC200 or NCC220 (like you can in the NAP180). You also have the option to replace the regulator boards with HCR200 modules. The overall topology doesn't change, and again the performance boosts are worthwhile.
  • In both the NAP180 and NAP250, you can replace the capacitor pair (with rectifier/s that feed them) with a CAP6. That's better, but not a major change, IMO.
  • In the NAP180, you can remove the rectifier and cap pair, then squeeze in two CAP6 boards. (This would probably require removing the pre-amp power supply.) The transformer in the NAP180 may have an extra set of secondary windings, so one can supply one Cap6 and the other supplies the second. Each Cap6 supplies a single power amp module. This is a dual-mono, but not "regulated" (no HCR200 or equivalent). If the transformer doesn't have a second set of windings, then there's no benefit to adding another Cap6.
  • The NAP135 is a mono amp, with a single transformer supplying the rectifier and pair of capacitors. This goes to the regulator board, then to the NAP module. It's a mono, so you need two boxes for stereo. It's similar to the NAPA250, except in two boxes.
  • With all the space you have inside the NAP180 (and NAP250 for that matter), some choose to by two of them, and convert them both to monos. Each will have its own transformer, followed by rectifier + 2xCap, or replaced with a Cap6. Now you have mono amps, with options:
    • If you're making a NAP180 into a mono, then you can add a regulation module (like the HCR200). (The NAP250 already has that equivalent.)
    • There's enough space to add a second transformer and cap6, plus HCR200. Assuming you have NCC200 or NCC220, you can use that additional supply to power front end of the amp boards, known as a Voyager.. (This doesn't work with NAPA amp boards.)
If you want a dual-mono Voyager amp in a single case, then you need 4 transformers, 4 CAP6 modules, two HCR200s, and two NCC2x0 amp boards. As I'm sure you realize, you can't fit that into a NAP180 case.

As you can see, there are many options, and you have restrictions depending on the size of the box.
 
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The above gives a good overview but there are a couple of points that should be clarified.
The NAP180 has a single power supply, which supplies both NAPA boards.
Actually, in the 180, each NAPA board has its own supply. The 180 transformer has two sets of output windings feeding two pairs of reservoir capacitors, one for each NAPA (the preamp supply is separately rectified and smoothed from one of the windings).

If you're making a NAP180 into a mono, then you can add a regulation module (like the HCR200). (The NAP250 already has that equivalent.)
The 180 doesn't really have the voltage overhead to do this without a transformer change. The 250 has secondaries giving 56v dc which is then regulated down to ~40v. The 180 has secondary rails at ~38v which doesn't give a lot of room for regulation.

If you are going down the monoblock route with a 180 and Avondale boards, running the front end from one 180 supply and the back end from the other 180 supply as mentioned above is a good solution. This can be done with the original supply or two CAP6s as suggested above.

I have done this with suitably modified NAPA boards (not Avondale) running off the standard supply and it works very well. However, using Avondale boards, rather than modifying the NAPA boards, would let you return the 180 to original spec if desired.
 
Are there different versions of the 180 with different psu setups? Google images appears to show most with what looks like the same psu pcb as the 140, but there's other images with 2 pairs of large caps. I'm assuming these are older CB ones.
 
All 180s are the same as far as I'm aware. The older pictures may be of 160s? The PSU board is the same as in the 140 but as 140 only has one winding on the transformer, the tracks going to the rectifiers are joined where the transformer cable attaches to the board.
 
The 140 has 4700uF reservoir caps where the 180 used 10,000uF. But you're right in that the board was modified for the 180 so that it could use two separate transformer windings. The 180 really was a parts bin amp.
 
The above gives a good overview but there are a couple of points that should be clarified.

Actually, in the 180, each NAPA board has its own supply. The 180 transformer has two sets of output windings feeding two pairs of reservoir capacitors, one for each NAPA (the preamp supply is separately rectified and smoothed from one of the windings).
Thanks, I wasn't aware of that.

The 180 doesn't really have the voltage overhead to do this without a transformer change. The 250 has secondaries giving 56v dc which is then regulated down to ~40v. The 180 has secondary rails at ~38v which doesn't give a lot of room for regulation.
FWIW, you can run the NAPA boards are much lower voltage. For example, I have my old NAP110 boards running in an amp with ±28VDC rails.

If you are going down the monoblock route with a 180 and Avondale boards, running the front end from one 180 supply and the back end from the other 180 supply as mentioned above is a good solution. This can be done with the original supply or two CAP6s as suggested above.
There's one point/clarification worth making: I once considered using a separate "smoothed" supply (transformer+recitifier+caps) to directly supply the front end of an NCC2x0 module. I was told that it wasn't worth the cost/trouble, if I didn't also add some type of regulation.
 
I once considered using a separate "smoothed" supply (transformer+recitifier+caps) to directly supply the front end of an NCC2x0 module. I was told that it wasn't worth the cost/trouble, if I didn't also add some type of regulation.

You might well be right - the NCCs already have filtering and diode isolation from the main power supply so a separate one might not add that much more.
For the NAPAs which don't, I found it had a large impact.
 
That's what I getting at, my 180 is standard and unserviced at present, so potentially without the power supply regulation it may be a little more 'exciting' than the 250. So I am left wondering about what to do with regard to upgrade path one the 180, my worry is that I will potentially lose that excitement if I mess around too much with the power supplies, maybe better to just replace the existing boards with NC200/220s and leave the rest as it is ? I have two 250s with less than 200 hours on since they were last serviced in around 2006 so well overdue for servicing too, and since they already have the regulation it may prove better VFM and improvement in sound to replace the regulation with some HRC200s and a Cap6 and maybe upgrade the amps with NCC220s.

I have been looking at Avondale replacement modules for years now and never had the nerve (or time and the money) to do anything about it, so I am keen to make the right decisions this time. I have the offer of some used NCC200s, HCR200s and a Cap 6 hence my thinking about where best to utilise them in my systems. Got to admit I am also seriously considering some of AA's other offerings, would love to try a Grad1 pre-amp sometime, or some of Les's passive SBL crossovers (I'm also left wondering if he can improve a NAXO 2-4) for an active option.

Lastly, you mentioned the 140 (my first ever Naim amp), what is the best upgrade for that, I'm asking because I may be in the position to help out a fellow Naim owner in Thailand (I introduced him to it over 10 years back) who has no technical savvy and has difficulty with servicing etc for his gear. If I could get the modules before I go out to Thailand this year (April) I could fit them for him and so upgrade and service all in one.


Please keep coming with the information, it's great to be able to take advantage of experience by others who have already dipped their toes in the AA pool.

I purchased a s/h NAP250 with NCC220/HCR200 boards to compare to my standard NAP250. The Avondale equipped unit is significantly better in every way!

I’ve also got Avondale crossovers on my SBL’s, a Grad 1 preamp, and TPX2 power supply. All of the avondale kit is an immediate and obvious improvement over the Naim equipment (72/hicap/250) that it replaced!
 
You might well be right - the NCCs already have filtering and diode isolation from the main power supply so a separate one might not add that much more.
For the NAPAs which don't, I found it had a large impact.
The point I was making that it needs to be both separate *and* clean. If you're just using a separate supply comprised of smoothing caps, then you might get a slight benefit, but not worth the expense and trouble of that supply. However, if you then regulate it with an Avondale HCR200, VBE, or equivalent, then you see a worthwhile benefit. That's why there are so many Voyagers out there, using the NCC2x0 modules.

The NCC300 modules include input stage regulation on the module itself, but it still benefits from having a separate, clean supply. The separate supply ensures that the output stage isn't causing problems with the input stage's supply. Additionally, Avondale will often add further regulation to the input's supply, to make it even better. That's what I have with my NCC300 monos, using the Avondale NCM1 module. The NCM1 includes a Soft Start Module, and a separate supplies for input and output stages on an NCC300. The supply for the input stage includes simple regulation using a zener diode. The cleaner supply means that the input stage has an even lower noise floor.
 
Apologies for the delay, work has been a bit crazy recently and I have hardly had time to think about anything else.

So, decision made I think, I will upgrade my NAP180 for now with a pair of Qudos boards (just purchased from Avondale) and a pair of Minicap 6 boards that I am still to find (and a rewire obviously). I was wondering about self-build Mini-cap6 boards, I am fairly sure Avondale used to sell them but I don't see anything on the website to suggest that they do now. If anyone has any bare boards for sale on the DIY classifieds please send me a link or a message - thanks
 
I purchased a s/h NAP250 with NCC220/HCR200 boards to compare to my standard NAP250. The Avondale equipped unit is significantly better in every way!

I’ve also got Avondale crossovers on my SBL’s, a Grad 1 preamp, and TPX2 power supply. All of the avondale kit is an immediate and obvious improvement over the Naim equipment (72/hicap/250) that it replaced!

I will look at the NAP250 upgrade later I think, the problem is that I have a pair of Olive 250s which intended to use in an active set-up and have never yet heard them that way (I only ever heard active 135s and that was 40 years ago nearly) so I would like to hear them first and secondly it would be pretty expensive if I decided to update both of them and maybe not great VFM in the end.
 

I wouldn’t touch Belgian Dada with a barge pole. There is something badly wrong with them these days. Please see them on Trustpilot. I have personal recent experiences of dealing with them very similar to the accounts on Trustpilot.
 


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