Marantz 2230 recap & LED conversion

[pingu_turbo]

Hi Guys,

I thought it time now to tackle the recap on my 2230. She has been in the wars lately what with the right P750 power amp deciding to shit itself, see here. A fellow blue lamp follower (Baseballhack) decided to donate a new P750 to me. I cannot thank him enough!

Anyway previously to the P750 amp board going wrong I had ordered a recap and LED kit from Robert Bowdish at I Rebuild Marantz to bring the old girl up to date. I have learnt alot about caps since buying the kit and probably would have chosen some slightly different ones, as in manufacturer, but I figured that Robert knows best as he does this all day every day. So I thought I'd stick with the original kit.

As a teenager I used to abuse this amplifier after inheriting it from my late Granddad. I nearly threw it away many years ago FFS! So after installing the new P750 amp board I decided to enjoy the 2230 for a while before ripping it apart again. So tonight I made a start.

I started by changing the power and the coupling caps. I thought this be as good a place as any as it will be easy to check my work after these 3 caps are installed. \/

The old ones \/

Before \/

After \/

Curiously the old power cap is a 4700uf 80v and the new one a 6800uf 100v. I did check the kit carefully, and that is right. What the differences in changing to this is I don't know. But Robert is the expert. Also the old coupling caps are 2200uf 63v and the new 3300uf 63v. Again why I don't know. If anyone has a explanation I would be curious to hear it?

Anyway all has gone well for this evenings instalment of my recap, I am listening to my 2230 as I type. Already it sounds beautifully warm, and inviting.:thmbsp:

 

[patfont]

It is ok to bump up them caps a little bit. Also what you are planning is best to follow, doing one board at a time and then checking your work.

 

[Leestereo]

The choice of the 4700uF/80V and 2200/63V caps in the 2230 are the result of the technology of time and the size/cost constraints for a mid-level model. This single supply topology receiver needs a single capacitor with a voltage rating that is about double the voltage rating that is needed in a same powered receiver that uses a split supply with +ve and -ve voltage rails. This power supply capacitor smooths the DC for the receiver and provides reserve power for the amp stages; generally, with higher capacitance values, there will be less voltage sag when the amp is asked to deliver power under load, which is desirable. In this case, IMHO, you can safely go to 10,000 uF without straining the diodes or the power switch much. If you are still concerned about the increase in capacitance, consider this comparison: the Marantz 1070 amp is rated at 35 wpc, uses a split supply and has a pair of 10,000 uF caps for a total of 20,000 uF in the PS.

Similarly, the original output coupling caps (2200uF/ 63V) can be doubled in capacitance value. Here the capacitor acts as a high pass filter to block DC from reaching and damaging the speakers. A higher capacitance here lowers the cut-off frequency as well as introduces less phase shift.

 

[pingu_turbo]

I think I have got it. That makes sense a bit more. Ill have to think on that for a bit whilst it sinks in. Thanks for that. :thmbsp:

Well, I thought I was going forward with this restoration, but clearly my OCD has got the better of me. I absolutely HATE the little caps in the holders. I know its progression and technology and all that but they look so puny and pathetic. So this evenings activities involved pulling them out again & putting the new caps inside the old cap cases.

I know some will probably disagree with what I am doing, but I cannot stand it. I know the covers on you can hardly see them, but you can and I know what's in there.

So I started off by cutting the edge of heat shrink off and prying the bent lip back on the old cap.

And finishing off with the needle nose pliers.

Pulled the old inners out.

Cut off the old aluminium rivets to retain the original solder tabs.

Put the new cap through the holes and soldered the cap directly to the tabs.

Then put it all back together, and fold the lip back over. First putting some rtv inside the cap lid to bond it in place.

Repeat one more time..

Then I did the same to the power cap.

Only this time I wasn't so lucky with the prongs of the cap, so I had to nut and bolt the old solder tabs on place on the cap lid with some solder contacts inside the cap body to solder the new cap to inside.

Sorry about the poor soldering here, I did re do it.

Ready to go back inside the old cap body.

All installed again, back to square one. I dont know if you can tell but I am playing music again, just a quick test.

Phew, feel better now. OCD pains fading.

 

[catrafter]

:thmbsp:

I hated those little caps bushed out to fit the clamps. This is a lot better looking.

Tom

 

[patfont]

I am glad to meet someone more OCD then myself. You did your Grandad right be making that 2230 look really nice. It is a wolf in sheeps clothing now, looks unrestored but in fact is!

 

[Leestereo]

Very nice cosmetic restoration to match the electrical one!

 

[bktheking]

When it doubt, cut the inside out. Glad to see you did that, maintains the look. Did that to my ka-6000 with the beercan cap and all the rest.

 

[Rasputin47]

Nice work :thmbsp:

 

[VintagePlus]

Looking great!

 

[bktheking]

You know something, this "kit" as it's called bothers me. Robert should know better than to sell a kit that doesn't fit. My question would be, is this the same kit he installs in customer gear? EDIT- just went to his site and indeed he's stuffing holders with foam. Yet when you look at the kit, the caps are the proper size and show a disclaimer claiming "this is a representation of a cap kit". For $79.75 sure you're getting a kit, but it just isn't correct IMO.

You'd think being an "expert" in the field of rebuilding Marantz gear he would send the correct size parts. Not that there's anything wrong with the "brand choice", I use Nichicon too, I would never expect my customers to have to cut caps open to maintain the proper fit. At the same time the leads are wrong, I typically use snap in caps for the PS and solder rings on. I don't know, maybe my expectations are too high but I can bet dollars to donuts if I sent my gear to any of the Marantz restorers on here and you know who you are it would never happen.

Pingu, I applaud your work, it's quite the opposite of can't stand, I couldn't stand it with those caps installed, now it looks like it should-Bravo!

 

[pingu_turbo]

Many thanks for the kind comments, esp patfront, that was a nice thing to say. I must say bk, I haven't really given it a second thought. Like you I saw his website and just assumed that some 'make do' would be needed. I am not really bothered about having to cut open the old caps, I see that it's my bother being so OCD. But I see what you mean with the tabs. All that matters is that is done now and I am happy with the result.

I plan to do the power amps next so I can check those too. Although now I am wondering about the choice of brand that is included in my kit. After having read patfronts cap shoot out thread. I can't remember what they are, I'll have a look when I get home from work.

 

[patfont]

Alot of people will end up on the IRM site when first checking out a rebuild for classic Marantz. To be polite his kits are marginal quality wise. The good news the Nichicon you installed are good. You have a very positive attitude about your rebuild. If you post up a pic of your Preamp board, I will send you some nice caps to install at no charge. PM me your address. I need a pic to see which version you have. Maybe others may kick in for other boards?

 

[catrafter]

If you search this forum, you will find cap lists for many Marantz units. Check the list against what's actually in your unit to be sure, then log on to Mouser or Digikey and order up what you need. Save some money and get high quality parts that fit properly.

Tom

 

[pingu_turbo]

Many thanks patfont that is a very kind offer. Also that was kinda the nudge I was looking for. I think I'll put this 'kit' in the spares box and make my own. I am going to have to read you cap shoot out thread again to make my mind up what to go for. You say the coupling caps were ok, but what about the power cap? Is that junk too?:scratch2:

As requested, here is my pre amp board, P400 if anyone wants to know.

In my defence, yes I did find IRMs website via google, but also at that time I new absolutely nothing about recapping a receiver. Yes I can solder and yes I can fit parts but nothing about audio capacitors, or even the fact they can sound different with varying qualities. I have learnt so much being a member here and just by getting my hands dirty.

I really enjoy doing this kind of thing. Going above and beyond what is worth doing to make it worthwhile, if you catch my drift!

BK, I do intend to do this to the 2215b you sent the fascia for soon. :thmbsp: And thanks for the encouragement. :yes:

 

[patfont]

What is in the kit for the Power Supply:

470uf 63V
330uf 50V
100uf 50V X2

I have some other caps laying around.

 

[bktheking]

To me it's all about the ears, what sounds nice may sound bad to another. As far as i'm concerned a good quality 105 degree cap, beit elna II's, nichicons, panasonics, they are all good caps. Going out and spending $50 on a pair of caps vs a pair for $5 may be considered a pursuit of sound but I'm frugal so i'll spend $5 and keep the $45 to buy the next score at the thrifts, it's how I roll. Others may choose to spend $50 on a pair of caps, to me, most of it is marketing. Sound is subjective. I've rebuilt 2270's and the owners are blown away by the sound. And it wasn't cause I spent $800 in caps, more like $80 in caps. They are new caps, new caps always sound better than old no matter what (unless they are old oil caps in a tube amp, different story). This is all SS stuff, unless you drastically modify a circuit caps won't have "that" much of an effect as far as I'm concerned. Speakers, wire, room- too many variables to make that kind of call without the proof.

 

[pingu_turbo]

In the PS kit there is:

C803 470uf/100v
C804 330/63v
C805 470/25V
C806 330/63V
C807 3.3/50V

Pat, please don't think I am after all your caps. I don't want to rob you blind! Just some recommendations would do.:thmbsp:

Bk your quite right, many variables, too many to measure. All I want to do is do this recap once and to the best of my knowledge. Every day is a day at school!

I'm frugal so i'll spend $5 and keep the $45 to buy the next score at the thrifts, it's how I roll.

That is me too......

Having said that I want to do the best I can with this receiver as its a bit of a special one to me as you know. All I can do is follow others until I have formed my own opinion and I won't know that until its done. Believe me I don't have bottomless pockets for things like that either, I don't think I would ever spend that amount on caps unless money were no object. I wish! If it were I'd have loads of old gear around with too many projects on the go!

Also does anyone have a recommendation for thermal coupler compound for when I get to re seat the transistors?

 

[patfont]

IRM provides Lelon e-caps I am not very impressed by them. Just wondering what brand he sent for the Power Supply, if they are Elna (doubt it) Nichicon or Panasonic FC that would be great.

 

[patfont]

Who is putting 50.00 caps in a Marantz?