| Sander |
Hi,
There are lots of dutch people on this forum building (or intend to build) the Aleph-X amplifier. Maybe we can arrange a groupbuy so we can buy the audiophile parts together? I was thinking about the resistors, (source) caps, transistors, transformers etc. Maybe we can also get a good heatsink offer for example. Hope to hear from you!
Sander |
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| TheJudge |
Hi Sander,
I was making some phone calls today.
I called Amplimo for 1000VA transformers, with a nice black aluminium round enclosure. :) They call me back because the enclosure for 1000VA is not standard. Also I know these guys, maybe I can get some discount.
Also we can order from Farnell, the higher the quantity, the better the price.
I was also looking for heatsinks. I have found really nice ones for around 450 Watts, but they were 120 Euro's, yikes!
Also have a look at this:
http://www.conradheatsinks.com/products/single_f.html
Unfortunately their biggest heatsink is a little to small for my amp. I want to go with 25VAC, 16 FET's, 8A Bias.
I've send them an email to ask weither they ship to The Netherlands or not.
Have a nice day. :) |
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| rwagter |
Conrad does send to the netherlands. I was involved in an earlier attempt to buy heatsinks from down under, this was the offer I got:
>MF30-151.5 x 10 @ 42.90ea. 429.00
>Delivery (FedEx Air 3-4 days) 225.00
>Delivery discount to overseas - less 50% (112.50)
>Total
541.50 (EUR328.23)
Because of the weight 10 pieces is maximum to ship with fedex otherwise it will be by boat (which takes up to 6 months :bigeyes: )
Good luck on your attempt
Ralph |
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| rtirion |
Duck-Twacy,
Thanks for the link. I have 8 pieces (250mmx300mmx84mm) of
this DEF103. Been saving them for a serious AX.
Couldn't find any info on them, so I did some measurements a
while ago.
Results are quite similar to the graph in your link.
These are anodized sinks (transparant)
Salvaged them from a scrap yard.
Regards. |
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| TheJudge |
Any idea what they cost?
I like the visual appearance of these better:
http://www.seifert-electronic.de/im...ics/kl-273z.gif
But they cost EUR120,- for 150mm length. :(
http://www.elincom.nl/
But with $112,50 delivery costs Conrad aint cheap either.
Caps for the power supply are expensive too. I've looked at Farnell and Conrad. Any other options? Is the brand important?
We could also buy IRF9610's together so we can match them nicely. :) |
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| dw8083 |
Just FYI... Check the heatsink prices at MM Metals www.mmmetals.com or ThermaFlo www.thermaflo.com.
With the dollar/euro conversion the US stuff has to be cheap. I just got a great bid from ThermsFlo for my AlephX heatsinks.
Just a thought.
Good luck,
-David |
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| Duck-Twacy |
No sorry you have to ask them.
I bought a 300*200*86 mm Seifert for around €65 at Clofis (ex btw) |
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| TheJudge |
Thanks David, the Thermflo heatsinks look really nice.
Duck-Twacy, calling them tomorrow. :) |
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| Sander |
I'm glad to see members interested in a dutch groupbuy! :)
I've found a dutch heatsink reseller nearby. It is Deltour and stationed in Amsterdam. The site is currently down, but I've seen useable heatsinks. When I know how many members are interested I'll ask for an quantum heatsink price.
www.deltourheatsinks.nl
Reichelt.de sells 800VA toroids. Do they look interesting to you?
Price: 55,80
800VA Reichelt Toroids
MOSFETS?
IRFP 044N 1.05/pc
IRFP 240 1.25/pc
Does somebody know a good audiophile passive component reseller nearby?
Offtopic: Pffff...Ik moet nodig weer eens oefenen met mn engels. ;) |
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| Duck-Twacy |
| quote: | Originally posted by TheJudge
Thanks David, the Thermflo heatsinks look really nice.
Duck-Twacy, calling them tomorrow. :) |
Thermflo is also in my favorites, as is this one
http://www.alutronic.de/e/indexe.htm
(btw I'm not in the market for aleph-x parts at the moment, just giving some help)
You can probably also buy matched mosfets at http://www.specmail.nl/ |
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| illusionxx |
Sander,
why not go for a European or even Worldwide Groupbuy for the MOSFETs ? The total quantity would shurely be much higher and the matching of the FETs could be closer.
Furthermore all lightweight parts are interesting for a big groupbuy in order to get lower quote.
Would be happy to jump on the groupbuy,
illusionxx |
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| TheJudge |
I think that's a good idea. I've read that especially the IRF9610 is very hard to match, and you will need a lot of them to get one good pair.
Alex |
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| TheJudge |
Just called clofis.nl,
The KL-273/150/sw heatsinks cost EUR91,- ex BTW. That's EUR29,- cheaper. :) |
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| Duck-Twacy |
| I also remember you can get a 5% (!) discount if you order 5 or more (or was it 10?) |
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| Sander |
@ The Judge:
Did you in the meanwhile heared anything from amplimo? Components from Farnell are pretty expansive and they haven't got any other audiophile qualified parts. So maybe whe need to buy them outside europe. (digikey / mouser for example).
I think it is best to buy the heatsinks in Holland. Shipment costs are enormous.
Capacitor brand seriously does matter. Unfortunately conrad hasn't got any "good" caps in stock. Those Panasonics @ farnell are pretty expansive, but they're also very good. (So I've heard) Does somebody know any good capacitors with reasonable prices? (screw-lock)
Yes, Transistor matching is indeed an advantage when we buy large quantities.
@ Duck Twacy:
Thanks for the links. Deltour is pretty nearby. So maybe I can get the heatsinks by car to decrease postal costs. This is a strong argument to buy them at Deltour, I think.
@ Illusionxx:
I'll think about an European groupbuy for the active/passive components. These parts should fit directly into your mailbox. Sending packages with components would be to expansive I think (toroids etc). Worldwide looks a bit risky to me. (disappearing packages for example)
I hope I didn't forget anything. :) If I did ring a bell. :P
Currently I'm searching for good Heatsink resellers... (Brrr...those are expansive :'( ) |
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| TheJudge |
There are a lot of choices to make when building an amp, and everybody has his budget. For example you can get cheaper transformers then the Amplimo's, but I like the round, black, metal case. And if the Panasonic caps are good, I will try to get them for a reasonable price.
There's a Panasonic office in Belgium, I could give them a call.
Farnell is expensive with everything, so it must be possible to get them cheaper.
I'm still doing a lot of reading about the Aleph-X. I will make a list of components that need to be of audiophile grade/high presision. I will post it here so we will get an better overview. |
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| illusionxx |
Those Krummer caps are the same as the ones from Mundorf and Thel
(http://www.thel-audioworld.de/bauteile/elkos/elkos.htm).
I don`t know the prices of the Mundorf caps but Thel takes 69€ for 1!! 47000uF @ 63V.
Those have low inductance(L= 12nH;tan-d = 0, 22;
ESR typ = 0,005Ohm ) and are designed for high ripple current (up to 100A without heatsink) and can be mounted on heatsinks.
The component live also is very long ( +40° = >540.000 h
+85° = >20.000 h).
Diameter is 91mm and hight 70mm!
Seems like the best elko we could get. But Krummer only sells to OEM customers. I think the only way to get affordable prices is to buy these elkos as a company and in very high quantity. Maybe anyone of you Holland folkes has the opportiunity to do this. Maybe i could do it over the company i`m actual working in. I`ll have to ask them.
So check out these elkos. I´m shure you will like them.
illusionxx |
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| TheJudge |
:checked: My father doesn't mind ordering some caps for us.
Just made some phone calls, looks like the Mundorf caps are only available in Germany. I still could try herweijerelectronics.nl (after 17:00).
There's only one problem, the price. I need twelve, that's around EUR600. :bigeyes:
That's a big no. I thought the Panasonics were expensive.
And we don't no if it's worth it until someone builds an amp with them...
I will continue my search for caps later today. :) |
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| byteboy |
I found out the same things last night as "illusionxx" did comparing info on the capacitors from the different web-sites.
The specs are impressive and they are sure top-quality products, but the prices are indeed rather steep!
At this moment it would be good to have some idea about the actual interest of people in and quantities of the different parts.
Best would be to setup a WIKI and define some categories.
Category's I found so far:
- Heatsinks
- Transformers
- High capacity electrolitic capacitors
- Power Mosfets
- ??
Per category some global spec's should be defined which could be a base for obtaining price quotations and allow some comparison between different quotes.
I would volunteer to set up the WIKI, but would have to look into the subject as I have no experience with that. |
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| illusionxx |
TheJudge,
im talking about buying the caps from Krummer (original manufacturer of the Mundorf M-Lytic HC caps and the Thel caps) -> same caps different label.
http://www.krummer-kondensatoren.de/index.html
I think the price would probanly drop to 50% ( estimated 35€ for 47000uF).
You don`t have to be a company to buy for 60€!
I think you calculated with 12*50=600€ (for 12*22000uF)? I think this would be a lot less with my intention.
I`m talking of the Serie 901 elkos.
http://www.krummer-kondensatoren.de...banschluss.html
Maby you could ask for a quote at 100 pieces so we would have a price for further considerations.
illusionxx. |
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| rwagter |
MOSFET : reichelt IRFP044N for €1.05 a piece irf9610 for €0.45 (both IR not Harris)
Source resistors: digikey panasonic 2W (same as NP uses in commercial XA's ) $0.28 a piece
Caps (nonPSU): If you want to go expensive and use BG's
acoustic dimension do have some time though, the guy is not the quickest, but relative cheap. If they are to expensive use panasonics and order at digikey since you are already placing an order of resistors ;) (and of course cl-60 's for your PSU)
Trafo : Reichelt 800VA for €55.80 (get good comments) use 2 instead of one if VA is not enough
Heatsinking
:confused: fisher is beautiful but expensive, seifert less expensive but not straight, deltour expensive and beautiful, US companies not really an option due to shipping weight with +10 pieces (these heatsinksink required are really massive !!)
Ralph |
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| TheJudge |
| quote: | Originally posted by rwagter
[B]MOSFET : reichelt IRFP044N for €1.05 a piece irf9610 for €0.45 (both IR not Harris)
|
Digikey has the IRFP240 for $1.49 (100 pieces), that's a little cheaper then Reichelt, maybe nice if allready ordering from Digikey. Don't know which one is better, IRFP044N or IRFP240 for my amp.
| quote: |
Source resistors: digikey panasonic 2W (same as NP uses in commercial XA's ) $0.28 a piece
|
The 5% METAL OXIDE ones? I've read low inductive types are preferred. Maybe we could buy some extra to get them matched. :rolleyes:
| quote: |
Caps (nonPSU): If you want to go expensive and use BG's
acoustic dimension do have some time though, the guy is not the quickest, but relative cheap. If they are to expensive use panasonics and order at digikey since you are already placing an order of resistors ;) (and of course cl-60 's for your PSU) |
There are not many caps in the Aleph-X, so I think I will go for the BG's. The guy is in The Netherlands, which is an advantage.
| quote: |
Trafo : Reichelt 800VA for €55.80 (get good comments) use 2 instead of one if VA is not enough
|
These are as big as the Amplimo 1000VA. Interesting. |
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| Duck-Twacy |
Those prices ar way to high!!
I'm afraid Soundline prices will not be that friendly either, it is just expensive stuff (but you can say hello to René from me, he knows my nick) |
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| TheJudge |
| quote: | Originally posted by illusionxx
TheJudge,
im talking about buying the caps from Krummer (original manufacturer of the Mundorf M-Lytic HC caps and the Thel caps) -> same caps different label.
http://www.krummer-kondensatoren.de/index.html
I think the price would probanly drop to 50% ( estimated 35€ for 47000uF).
You don`t have to be a company to buy for 60€!
I think you calculated with 12*50=600€ (for 12*22000uF)? I think this would be a lot less with my intention.
I`m talking of the Serie 901 elkos.
http://www.krummer-kondensatoren.de...banschluss.html
Maby you could ask for a quote at 100 pieces so we would have a price for further considerations.
illusionxx. |
Would you be so kind to call them for me? Since you speak German. :)
I would appriciate it a lot.
47,000uF and 100,000uF @50 Volt or 63 Volt. 12 and 100 pieces.
I don't know where others are interested in?
Ripple CRCRC 25VAC Full Bridge:
Krummer 47,000uF 47mV
Krummer 100,000uF 5mv
Panasonic 150,000uF 1,8mv
De Krummers have lower inductance and 5 times higher ripple current...
Unfortunately numbers doesn't say a lot about sonic diffrences. :bawling:
Maybe I should ask Nelson. |
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| illusionxx |
TheJudge,
at Krummer they`ll only give informations if you can name a company you are asking for.
But you could use this form:
http://www.krummer-kondensatoren.de/html/anfrage.html
and make the following entries:
>Bauform: Schraubanschluß
>Befestigung: Gatter Becherboden
>Kapazitaet: 47000
>Betriebsspannung: 63
>Jahresbedarf: 100
>Losgroesse: 100
>Baugleich zu: Serie 901
And the fields under
>Bitte geben Sie nachfolgend Ihre Kontaktdaten ein:
have the following meaning (from top to bottom):
>Name
>First Name
>Company
leave the next two fields blank
>E-Mail
You can post the reply or e-mail it to me and i`ll translate it for you.
| quote: |
Ripple CRCRC 25VAC Full Bridge:
Krummer 47,000uF 47mV
Krummer 100,000uF 5mv
Panasonic 150,000uF 1,8mv |
Perhaps you should try CLCLC. This will give you ripples of 4mV peak to peak with 44000uF caps and 1.2 mH inductors.
illusionxx |
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| TheJudge |
I've contacted Soundline yesterday. The 47,000uF 80V go for EUR70 when you buy 100. No lower voltages available.
Last hope, direct from the factory. I habe das anfrage formuliere gebraucht. Ich hope das they understand was ich wolle.
Thanks Illussionx. :) |
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| Leeuwarden |
| quote: | Originally posted by rwagter
seifert less expensive but not straight
Ralph [/B] |
I called Clofis about this problem last week. They were suprised to hear the heatsinks were not staight. They said that's not normal. So I ordered new heatsinks for my second Aleph 5 and asked if I could return them if they were not straight. They said that I could return them. |
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| Magura |
You could take a look at www.svalander.se for PSU caps.
AFAIK the rifa peh169 is among the best, and for the price at svalander, close to unbeatable.
I bought a handfull of the 100.000uF 63V type for my project, I am still to find a cheaper or better solution.
Magura:) |
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| Tarasque |
Guy's,
I'm running the 800VA toroids in my class-A amp to 60% of the load. They remain cool (~20C above ambient).
I've used these transformers also in other projects and the 800VA have power to spare. If compared by the delta temperature with the 300VA, the 800VA is essentially a 1KVA with higher copper loss. My guess is that BSAB is using a 1KVA core.
BSAB is the supplier for Reichelt and is also delivering custom build toroids for intresting prices.
Also happen to have some 20 heatsinks left with a 10mm base plate measuring 200 (W) x 120 (H, also fin height) X 40 (D) weight: ~1Kg each.
For high capacity heatsinks you could also look at the bonded fin solutions of Thermalloy. |
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| illusionxx |
Magura:
| quote: | You could take a look at www.svalander.se for PSU caps.
AFAIK the rifa peh169 is among the best, and for the price at svalander, close to unbeatable.
I bought a handfull of the 100.000uF 63V type for my project, I am still to find a cheaper or better solution.
Magura
|
Krummer caps have a little better specs and if we get a good price at the factory this might be the solution your looking for.
TheJudge:
Glad to her that you took use of the "Anfrage Formular" .
Tell me when you need translation for the reply.
illusionxx |
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| kro5998 |
| Why not try BC (vishay) capacitors. Computergrade 105C.They are about the same price as panasonic and have better specs than Krummer. |
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| smallsun |
Hi Sander,
Do you find the heatsink for your Aleph X amplifier? I was organizing a group buy of heatsink Aleph amplifier chassis.
Would you like to use this chassis to reduce heat rate.
Here is the image of the chassis:
http://www.diyaudio.com/forums/show...=5&pagenumber=3
If you have interesting our chassis, Please e-mail or through this forum to contact me at sun238@yahoo.com
Thanks,
Sun Cheung |
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| jacco vermeulen |
| Do you know by now what the parts will be that you intend to order ? |
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| illusionxx |
All specs are for 47000 uF @ 63V
BC Serie 154:
ESL 29 nH
ESR 9 mOhm
RIFA PEH169:
ESL 17nH
ESR 5 mOhm
Krummer Serie 901:
ESL 12 nH
ESR 5 mOhm
I could only find BC`s rated at 85°C (the others are also 85°C). Maybe the 105°C types have better specs.
Perhaps kro5998 could post a link to the specsheet.
And here is another label for the Krummer caps:
http://www.winkel-kondensatoren.de/pdf/FTcapSerieGW.pdf
I`m going to ask them for a quote if the one from Krummer isn`t good.
illusionxx |
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| JochenH |
Unfortunately, the BC series 114 / 115 has been discontinued, they had 3mOhm ESR / 20 nH ESL.
The current series 101/102 and 106 don't come close to this. Perhaps you can find some 114.
Here is the link to the data sheet: BC series 114
Jochen |
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| kro5998 |
I am planning to use the BC 058 series.
10 *10000uf/50V in parallel per rail which should give me a rated ripple current of 50A and an ESR of 3.7mOhm.The inductances would also be parallel.
www.vishay.com/docs/28342/058059pl.pdf |
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| byteboy |
Why focus only on the larger values like eg. big 47,000uF caps for the capacitor banks?
It may be a gain in occupied space, but is the ripple supression of a well designed PSU with multiple rc-sections (= more and smaller C's and smaller R's eg. (R)CRCRCRC) or just more paralelled C's) not better than or at least equal to the same total capacitance achieved with say just 2 large (expensive?) capacitors?
Advantages could be:
- Lower inrush current phenomena?
- A lower price for the larger total quantities ordered in the group purchase?
- More flexibility for people participating in the GP to choose the total capacity in the PSU, eg. for people who wish to build a "standard" AlephX (20 - 40 Watts) requiring less capacitance in the PSU.
In this view I would suggest a max. capacitance of 22000uf per device.
Any thoughts? |
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| illusionxx |
The price of a 47000uF cap is usually much lower than 4 times the price of a 10000uF cap!
To parallel for example 2*22000uF shurely gives a better result but it is also more expensive. In the case, that a lower price for the larger total quantities ordered in the group purchase equals the higher costs
for the smaller caps, this would shurely be the better solution.
illusionxx. |
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| TheJudge |
| Maybe I stay with my first idea, CRCRC with the Panasonic 150,000uF 5mOhm caps (Eur28/pc). Ain't that expensive compared to the other solutions. |
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| Jarno |
Hello all,
I didn't go through the complete thread, but did you guys read the article on Class A power amp supplies by Rod Elliott?
In the article, he prefers a greater number of smaller caps as opposed to a couple of big ones, based on the lower cost and larger ripple current rating.
I agree that the difference in costs between 10mF and, for instance, 22mF is not that big but the difference between 10x4700uF and 1x 47mF is about €3,60 (according to the excellent online catalog of Reichelt).
Regards,
Jarno. |
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| jacco vermeulen |
| quote: | Originally posted by Jarno
In the article, he prefers a greater number of smaller caps as opposed to a couple of big ones, based on the lower cost and larger ripple current rating.
|
Read some more :
Gunther mania
Grundlagen der audio technik
Stereoplay januari till august 1988
Reinhard Wachowiak
Audiolabor Fein + brillant
www.Audiolabor.de
Michiel de Goeij en edwin weetikveel
Sphinx project 12
Scylla Mosfet amplifiers
ESR ratio on average for capacitors of the same construction is Sqrt(C1/C2).
Meaning : 10 parallel 4700uF caps have an ESR value 0.0316 of that of a single 47000uF cap. |
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| jacco vermeulen |
| Which is why i bought a few hundred old production Roederstein EYF 4700uF caps a couple of months ago. |
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| TheJudge |
| quote: | Originally posted by jacco vermeulen
ESR ratio on average for capacitors of the same construction is Sqrt(C1/C2).
Meaning : 10 parallel 4700uF caps have an ESR value 0.0316 of that of a single 47000uF cap. |
Are you sure it's not 1 / (1/C1) + (1/C2) + etc.?
PSU Designer can't have caps in parallel, so I have to calculate them myself. |
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| jacco vermeulen |
| quote: | Originally posted by TheJudge
Are you sure it's not 1 / (1/C1) + (1/C2) + etc.? |
Nope !
Sqrt( 4700/47000) = Sqrt (0.10) =0.316
0.316 / 10 = 0.0316
1/ (10 * 1/1) = 1/10 |
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| JochenH |
This would mean that a single 4700 µF would have a lower ESR than a single 47000µF, which is not the case. Perhaps you swapped C1 and C2, so sqrt(47000/4700) = sqrt(10) = 3.16 (the 47000 is 3.16 times better than a single 4700). So 10x4700 are 10/3.16 times better regarding ESR than a single 47000.
Mmhhh. looks more realistic. |
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| byteboy |
Hi illusionxx,
Some time ago I did some calculations in Excel for myself.
I was aiming at using the F&I capacitors from Conrad, 22000uF/63V or 47000/63V and using their quantity discount rates.
At a total quantity of 104 (13 sets, being 2 banks of 4 caps of 22000uf per set) to get the 100+ discount, versus 52 (13*2*2 of 47000uF) to get about the same capacity it came out just under €5 difference in price per set!?
So pricewise there was no big difference.
Taken into account the other mentioned advantages and the fact that quantum discounts for 100+ pcs. are not that good at Conrad, I think the comparrison could be even more in favor of the smaller caps and that there is no real need to go for the bigger caps? :xeye:
TheJudge
I also tried putting in caps in paralel in PSU-designer.
I (kind of) suceeded only by using CR sections with the lowest possible R of 0.0011 Ohm (1.1 mili-Ohms), the resistance you might expect from wiring- and contact resistance etc.
I was suprised though by the results; the total voltage drop over these resistances was rather big and I don't know if I can trust these results. :bawling: |
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| jacco vermeulen |
Here is the section of the 1988 article in Stereoplay.
Sqrt (1/2) = 0.707
0.707/ 2 = 0.3535 ~ 1/3
Seems to be in accordance with the statement made. |
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| jacco vermeulen |
Did anyone of you guys read the posting of Mr Lgreen ?
He made the suggestion of a group buy and matching for Mosfets.
I am building 4 more Aleph's and 2 Zen XA's for which i need some 100 Mosfets.
I am supposing some of you may be in need for Mosfets too. |
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| Jarno |
Hello Jacco,
Maybe the guy(s) at Specmail can give you a quantity discount on matched sets? You might need less Fets if they are already matched, and maybe those guys are interested in delivering larger quantities?
BTW, that's a reallly nice stash of caps! You really have great dumpsters in which to dive!
Regards,
Jarno. |
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| byteboy |
Hi Jacco,
It was my reasoning to set up a WIKI for the Dutch group purchase, ie. to get an idea of the real demands for the different parts as a group purchase.
I was too busy however with other things and did not have the time to look into it yet how to do this and do some basic page set up.
I will look into it this evening (night? :D) and try to set it up.
People can state their interest(s) there and we can use it to see if a group purchase is feasable.
I will post a link here when it's up.
I will also have a look at the thread of Mr Lgreen, maybe we can work together with them.
Personally I am interested only in high quality transformers and -capacitors, (matched-) IRFP9610 and maybe other board components. |
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| jacco vermeulen |
| Yes sir, Boss ! |
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| illusionxx |
byteboy,
i`m not against small caps, but the calculation you did depends on the pricerange of the caps. More expensive caps will have a higher difference in price.
I was thinking of the Krummer caps also because of their long livespan of 560.000 h @ 40°C.
But taking into acount my financial situation i must agree that the best solution will be resonably priced small caps (let`s say 10000uF). This way it will be easy to hit the 100pc. pricebreak.
I think you`ll take some into the WIKI?!
In my opinion it`s the best to take the ESR values out of the datasheet and calculate with these numbers. So the ESR of 10 caps in parallel is 1/10 of the ESR of a single cap (simply parallel R`s). Same with ESL.
For example:
47000uF : ESR = 5mOhm
10000uF : ESR = 15mOhm
4 parallel 10000uF caps : ESR = 15mOhm/4 = 3.75mOhm ;
So we have 3.75mOhm against 5mOhm.
illusionxx |
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| jacco vermeulen |
| So, if you are hunting for low ESR, which is the better of the two ? |
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| jacco vermeulen |
So, if you are hunting for low ESR, which is the better of the two ?
btw :
it is common practice to place small caps on pcb's just before the sources/collectors of the Q's.
The reason being that small capacitors are much faster for impuls power than large caps.
Maybe one should differentiate between current going in the cap and current going out.
For low ripple in class A amplifiers i switched to very large capacitors long ago, going to higher and higher capacity caps.
I built Jean Hiraga's Le Class A for which i employed extreme big SCR caps. It worked well for the froggies, it worked for me.
Nevertheless, i still use large banks of small capacitors placed on powersupply PCB's too.
In my view combining a large capacitor in combination with a number of small ones makes much more sense than investing in esoteric capacitors like the one from Thel.
Magura's link for the Rifa 169 and 200 is high quality for the buck,
the Rifa's are among the best. |
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| illusionxx |
| quote: | | So, if you are hunting for low ESR, which is the better of the two ? |
I never had any doubt that multiple parallel caps are the best technical solution. My only worry was about the price.
| quote: | | Magura's link for the Rifa 169 and 200 is high quality for the buck,the Rifa's are among the best. |
I agree, very good caps for a good price.
Unfortunately they only have a few in stock, so they aren`t interesting for a group buy. |
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| byteboy |
Hi guy's,
I have set up a basic WIKI-page for the GP.
It's located at:
Dutch Parts Group Purchases WIKI
It's far from complete yet, please ammend, correct and complete!
Have a look and don't forget to state your interests in the different parts in the table at the bottom. |
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| Jaac TheMaster |
hi you all
i reading this forum from the beginning and i am also intrested, i have filled in on the wiki page ( looks goo).
any news on the heatsink's ??
gr Jaac |
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| jacco vermeulen |
Did someone take a look at Airlink transformers in the UK ?
Airlink produces toroid transformers in Holden&Fisher style, their rates for multiple numbers are known to be very attractive.
Often, a custom order is cheaper than one of their regular production types. |
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| byteboy |
Added an entry for power resistors and did some minor changes/corrected typo's.
Jacco,
I hope you didn't edit other things besides your entry in the inventory table because it seems we were both editing at the same time and with WIKI's things can get lost then......:mad:
I will take a look the Airlink transformers in the UK, thanks for the tip! |
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| kro5998 |
Has anyone tried Rod Elliots capacitance multplier?
I build a test setup consisting of a variac,16V transformer,35A bridge and 47000uF capacitor.
I tested with and without the multiplier and loaded the cirquit with 2.8 Amps.
Without the multiplier i got a ripple of 600mV pp.
With the multiplier the ripple was less than 1mV pp.
The losses across the transistor (2n3055) where 2.35V and stayed the same even when i doubled the load.
With a CRC or CRCRC filter the losses would be much greater and would vary with the load.
Has anyone tried this schematic out on a real amplifier and can comment on the sound? |
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| byteboy |
Hi kro5998,
Good results you have gotten it seems with the capacitance multiplier!
I have no experience with this circuit in an actual amp circuit but I intend to use it in an AlephX I am building at this moment as a kind of "prototype" with components I already had in my junkbox.
I want to gain some experience with the AlephX circuit, before spending big buck$$ on the realy expensive parts like high quality PSU capacitors and -transformers.
One of the things you encounter when building with parts you already have is that you will have to improvise.
In my case this means I have a number of capacitors with too low capacitance (although physicaly they are big) and higher than strictly neccesary working voltage (6800µF/63V) and a transformer with non optimal secondary voltages (12-18-24 Volts AC / 320 VA) for a "straight, C-only" PSU for a target power of abt. 100 Watts @ 8 ohms.
I figured it would be an ideal case to put the cap multiplier to work; bleeding off the excess voltage in the cap multiplier and putting it to some good use at the same time too. :cool:
I've read posts of people having good results of using this circuit in different types of amps on this forum.
I don't know about the effects on sound quality of the used type of series power transistor, but I could imagine a difference.
I remember Rod Elliot suggesting a TIP3055/TIP2955 there, but not for sound reasons.
I wonder how a MOSFET would do there soundwise?
But like I already said, no experience myself, that's what this "prototype" (for which I'm currently working on some kind of chassis to house the - rather bulky - parts) is, amongst other things, going to be used for! |
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| jacco vermeulen |
Capacitance multiplier reads to me as a regulated powersupply.
Mr Elliot uses 2955/3055's all the time because they are cheap
and have a prooven history, nothing wrong with that.
Audiophile did an amp design with a regulated powersupply for the output stage a number of years ago.
One of the American names produced a fully regulated poweramp once too, my memory fails me for the model and brand.
I bought the old stock of the company that produced the sound equipment for the Rijkspolitie Porsches.
TIP's were used for the output stage, i employed a number of the complete output modules as shown on the picture for BMM's
2-30volt/15 amp lab power supply.
I still have loads of these modules and chassis, already thought about using them to build something like Elliot's CM.
Voltage regulation is common practice in pre's and front end circuits, if a CM/RPS is fast and able to deliver multible amps of current i see no reason why it should not be better soundwise.
The whole idea of a powersupply for output stages is that it should be able to keep voltage level as constant as possible while delivering high currents.
That is what the big tories and large capies are there for.
I tried car batteries for the power supply of a class A power amplifier once, combined with a batteryfed preamp.
It sounded way better than the 300VA toroid/ 75.000uF powersupply.
Downside was the stack of 12 car batteries,and replacing $1000 of maintenance-free ACDelco's every 5 years.
I have seen a design that used MJ1500**'s instead of TIP's to lower the number of devices for the power regulation.
Sonically i see no reason to use other than 2955/3055's as the frequency is merely 100Hz and DC is supposed to come out, Elliot's choice for them in this case is certainly the best.
Excellent subwoofer amplifiers can be built with 2955/3055's.
If lowering transformer voltage is needed, and the powerloss is no problem Elliot's CM is a very nice idea.
You may like to read Audiophile's article on
"L'Amplificateur Fou, Fou" by Hephaistos, summer 1990.
It uses a triple V-Mos regulation for the output stage.
` |
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| byteboy |
Hi Jacco,
I think what it all comes down to with power supplies for power amplifiers is the capability to deliver the power quantities required by the output stages at any time, fast and without sagging in voltage or current.
For this you need a big power "reservoir".
The solution with a stack of car batteries as the power reservoir is I think almost perfect in this sense, the Nr. 1 solution, but at the cost of a high price tag and beiing a bulky solution.
The regulated power supply with big, high power, high quality transformers and big, high capacitance, high quality capacitors as the power reservoir is I think second best, but with more complexity and power dissipation losses.
The unregulated PSU with a CRC(RC) or CLC(LC) is a relatively simple solution, but sill requiring high quality transformers and capacitors as the reservoir.
The capacitance multiplier is I think a good compromise between a regulated and an unregulated PSU.
It will have much better ripple rejection than the unregulated PSU and less power dissipation than the regulated PSU but at the cost of having worse absolute voltage regulation.
I like to think of it as a CLC PSU, the "L", the inductor, beiing formed by the capacitance multiplier ("gyrator-"?) circuit.
(a gyrator is an electronic circuit without inductive components, just R's, C's and active components, emulating a (large-) inductor, for those who don't know)
A PSU with just an enormous amount of capacitance as a reservoir to suppres ripple is the simplest and most straight forward solution but will require lots of expensive capacitors and special care with respect to the high inrush currents due to the high capacitance values.
Take your pick....;) |
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| kro5998 |
As mentioned on Elliots site the multiplier is not a regulated PSU.
Even with the currents i am planning to use on a low power Aleph (4 amp total per channel) it still needs a huge CRC or CLC filter to get this low a ripple current.These would require big R's or L's
which have considerably more voltage drop across them.On top of that these losses would increase or decrease with the load and thus the output voltage would vary accordingly.Try doubling the load on a CRC filter in PSU designer and see what happens to the ouput voltage.
Correct me if i am wrong but in my planned Aleph the ideal current distribution would be 50% per rail.Under load this could swing to max. 100% on one rail and 0% on the other.This means double the calculated rail current.With a CRC or CLC filter this would result in a considerably voltage drop on the 100% rail. |
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| kro5998 |
Hi byteboy, missed youre post.
I am also working with exisiting parts (transformer,bridge,caps,heatsinks) to try out the Aleph.
I have a preamp without balanced outputs so i would like to try out the Aleph first.
I am going to try a Mosfet in the multiplier cirquit but i think the voltage los would be greater (around 4 V).It won't need a darlington though.Also finding a good complimantairy pair could be a problem.P channel Mosfets would have different losses. |
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| jacco vermeulen |
My idea for Elliot's CM would be to use higher value primary and secondary caps and a device that handles a higher current than the 15 amps the 2955/3055 do.
Or, placing several BD139/140- Tip2955/3055 in parallel with the highest caps Mr Elliott advises.
Though it is not a fully regulated powersupply and voltagedrop will be lower, the inrush current for high value capacitors will kill the TIP devices.
I mentioned the heatsink/TIP combo's because i have so many of them.
Placing a number of them in parallel with a bunch of 4700 uF Roederstein's gives maximum ripple reduction, high inrush capability, and i need not spend on it.
The TIP's i have already have 3 parallel 0.33 Ohm emitter resistors on each device, placing 4 of them in parallel would work i think. |
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| kro5998 |
| Hi jacco, i used 5 * 6800 uf in front and 2 * 6800 after the 2n3055.So far no problems.A 2N3771 (30 A instead of 15 A) would be better though. |
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| byteboy |
I somehow did not receive the E-mail notifications for updates on this thread, so I didn't look here for some time!
I updated the WIKI a little bit this morning.....
Seems interests are less than expected?
Where are you guys, posting in this thread about building amps, but not requiring any parts? ;)
Please update the WIKI!!
I had a look at the website of Airlink Transformers. Nice and much informative website, but could however not find any info on earthscreened / shielded versions.
(From the WIKI it seems like I am the only one interested in high quality tranny's anyway....:( )
| quote: | The Judge
I was making some phone calls today.
I called Amplimo for 1000VA transformers, with a nice black aluminium round enclosure. They call me back because the enclosure for 1000VA is not standard. Also I know these guys, maybe I can get some discount.
|
Any news or info from Amplimo? Quotes/Prices? Shielding? Any other info?
kro 5998,
I think Rodd Eliot also described a symetrical CM PSU version with all NPN transistors? This maybe could be also done with all N-channel MOSFETS?
I don't know if I understand your question about the current distribution and I think this could be a major difference between an Aleph and an AlephX but the current distribution in an AlephX is said to be totally symetrical, ie. the + and the - currents are said to be (almost-) equal. So no problems with that there. :cool: |
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| illusionxx |
Hello to everyone,
hope you`ve all had a Merry Christmas.
Unfortunately the participation in this group buy is very low up to now.
Maybe the name of the thread is missleading. In fact i`m the only one from outside the Netherlands that is involved. And this is obviously not enough.
I think that clear statements will have to be made who is welcome to join into the groupbuy and who can`t take part.
It also could be helpfull to start a new thread - "European Groupbuy" - to continue this one at least for the small parts like the MOSFET`s and power resistors that are easy to ship.
But the most important thing is to keep the thread alive to get people`s attention!
The Judge,
did you get any reply from Krummer?
illusionxx |
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| jacco vermeulen |
Good suggestion, Illusionxx.
Maybe European can be looked at in a broad sense.
I can imagine that some of the British, Scottish and Irish fellows would like some parts from the continent.
Channel, frontier and language wise may be a burden for them.
It seems as many buy RS parts, not my fav place to shop.
I even know someone living 5 miles from the ferry terminal to England, willing to drive the heavy parts across the channel.
:clown:
I read plenty of postings by members from Germany, Austria,
"Die Schweiz", France, and Belgium.
Combining those might make this a real "Group" buy.
On another note:
i was wondering what kind of power resistors you are thinking of;
MPC's, more esoteric as Caddock 930's, or some other ?
I survived the Christmas dinner, still have 4 days to type postings till New Year's fireworks.
After 25 years of retirement i will be back on the 1st in an attempt to bomb my fingers off, maybe an eye or two. |
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| tschrama |
| I think that once the PCBs ahve arived... more people will suddenly be interested.....:smash: |
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| illusionxx |
I haven`t thought about the power R`s yet and i even don`t know which ones would be recommendable - most probably low induction types. With large quantities we could be able to get the esoteric parts for a reasonable price.
Maybe some people are also interested in highest quality caps for the small values in the circuit (220 uF).
Everybody`s recommendations are welcome.
To all the people that are new to this thread:
There is a WIKI to see what quantities a group buy can reach, that can be found here WIKI
So please sign in if you are interested or post if there are any questions.
illusionxx |
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| Duck-Twacy |
I'm sorry I'm not in the market for an Aleph-X rightnow (just contributed some hints). Currently I'm trying to finish my Aleph5 (for which all parts are already acquired) and a LCaudio Zappulse (for the lows). I purchased 4 Rifa's for the latter two weeks ago (very nice indeed).
I think for a succesfull groupbuy you have to a better focus what its for, so you have a good chance of getting a good discount. Having a single vendor helps with this of course. Also you need sombody who takes the lead (and who has enough time to do the organizing).
Personally at the momemt I'm only interested in some diodes such as scottkys or good bridge types such as Ixys for a 45 VAC PS |
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| kro5998 |
Hi byteboy, your'e right about the current distribution.Because the Aleph X is basically 2 bridged aleph's with inverted inputs the load differences cancel each other out.
I tried a N-channel mosfet in the Capacitance multiplier but the losses (drain-source voltage) where greater compaired to using a 2n3055.
I plan using the pair MJ11015/MJ11016 which are darlingtons rated at 30A.The Inrush current of the capacitors after the transistor are limited by the chargetime of the capacitor at the base of the transistor.
Do you have a link to the schematic on Elliots site about the PSU with only NPN transistors?Then I could use the cheaper 2N3771.(1 euro a piece).
Best wishes
kro5998. |
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| byteboy |
Hi kro5998,
I was wrong, I didn't see it at the ESP site and couldn't find it anymore.
(I guess I do too much reading about audio electronics on the net lately..... :) )
But a quick search with Google helped and I found it back, I saw it at:
The JLH Class-A Amplifier Site
It's a copy of the ESP site, but a version with the same type of power device (NPN 2N3055) in the "+" and the ''-" supply.
It presents a nice idea in the text too: Using the "rejected/leftover" power devices (in our case MOSFETS) from the matching process of the output devices for the powerstage of an amp as the series regulator device in the CM!! |
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| byteboy |
I did find the original article on the ESP site of course, but not the version with the identical series regulator device in the + and - :)
kro5998,
How did you do the CM with a MOSFET? (maybe a schematic?, what type of MOSFET did you use?) |
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| jacco vermeulen |
I know.
Just thought it easier to place the original version here too. |
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| Sander |
Hi, I'm sorry for not having participated in this thread the last days. I'm pretty busy with other things.
I think this groupbuy isn't gonna work out, bacause of the deversity of parts. Personally I'm not gonna buy $50 /pc caps. That's to expensive for a student. Lets say we only buy small signal conductors for pcb mounting? |
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| kro5998 |
Over the new year weekend i finished my capacitance multiplier boards. they use 98000uF per board and TIP35/36 as output devices (40 A).I am going to use EI-core transformers which i rewind myself.Output of the boards will be 2 x 14V/4A and the dissipation is around 24 Watt.
Total cost so far 8 Euro.Mostly used parts lying around.
Anybody know how to get a pair of HifiZen/Alpha boards?
I like them better than Kari's board because of the extra options(protecting diodes,compensation caps) and because i think Kari's boards are better suited for a high power Aleph-X. |
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| dr.strangelove3 |
| quote: | Originally posted by kro5998
Anybody know how to get a pair of HifiZen/Alpha boards?
|
Hello kro5998
I've got a pair of them. I myself am waiting for Kari's boards.
If you are interested you can mail me. |
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| illusionxx |
Sander,
i´m a poor student too, but maybe we can get high quality caps for a really good price if there are enough people participating in the groupbuy. I don`t think there are many people who want to spend extraordinary $50 per cap! But i can emagine some are willing to pay $25 for a $50 cap. It will be necessary to specify manufacturer, values and (low)prices to tempt people tu jump onto the groupbuy.
Kari is going to send out his AX boards at the end of january. I think the interest in parts will increase rapidly after people got their boards.
Untill then there is enough time to get quotes and specify part.
Yes one problem is that there are too much diverse parts we are talking about in this thread. In my opinion the most important parts for a groupbuy are the MOSFETs because of the need for matching which can be done very closely with a great number of devices. But we need to find someone who is willing and able to do the matching. Maybe this should be a seperate groupbuy cause i don´t think that anybody wants to handle a big groupbuy and the matching which will be a lot of work. The person who does this job could at least get his FETs for free!
Just some thoughts.
illusionxx. |
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| yldouright |
| Speaking of caps and the right resistance value to put in the PSUD2 modeler. Most ESR values are taken at 100khz so wouldn't it be more appropriate to use the 120hz ESR value? I wonder if the modeler takes this into account when it does its calculation. Which value ESR does the modeler expect to see? This information isn't listed anywhere in the help section so if anyone familiar with that program could help tell us the math on the PSUD2 capacitor resistance input I'm sure we would get more accurate results. |
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| kro5998 |
Just finished testing my multiplier PSU.
I set the output voltage at 13 Volts, the current as measured was 4.8 Amp per rail.(input is 13.5 Volt AC)
The upper trace is 2mV/div. and is the output.
The lower trace is 500mV/div. and is before the power transistor.
The collector/emitter voltage was adjusted at 3 Volts.
I use a SK01 heatsink of 200mm for the bridge and the transistors.Heatsink temp was 48 C. |
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| threefff |
Hey Illusionixx,
I bought 25 IRFP240 from reichelt, all out of the same LOT. I can use them all, matched in bunches of 6 within 35 mV.
The same with the IRF9610: bought 15 and got 3 pairs matched within 1 or 2 mV (I guess, that my measuring setup is not that accurate). The rest is still usable, according to the 10mV bandwidth N. P. suggests. I'm very pleased with the mosfets and the matching.
Cheers Thomas
P.S. Still need Heatsinks: 300mm x 150mm, less than 0,25 C/W |
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| illusionxx |
threefff,
did you tell them at Reichelt that you needed all out of the same LOT or did you just order them and had good luck?
Which board are you going to use?
Have you allready collected all the parts except the heatsinks?
I`m very busy at the moment so the AX has to wait. How much output power are you planning with?
illusionxx |
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| threefff |
Hi Illu,
maybe we should not highjack this thread for personal interests, but to be honest, I cannot figure out how to make my e-Mail adress visible in the user data and yours is not visible either.
Anyway, your questions:
- Yes, I told them
- Im building aleph2s and use a board I found on the forum intended for aleph4s.
- Yes, almost. I bought 70 caps Paccom ES 15.000µF 63V for 50 Euros altogether at J.E.A. (you'll find him in the stores of ebay.com) Shipping was somewhat expensive for 29 Euros. ESR is not too bad and not too good, so paralleling is the choice.
Besides the heatsinks I still miss inductance free resistors. Probably I'll take Allen Bradley carbon comp resistors for the low wattage and MOX for the high wattage.
But that will be the future, let's see how it all turns out before I'm finished.
Have fun
Thomas |
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| threefff |
Hi,
so let me get back to the heatsinks.
deltour offered me the DEF26 in black anodized with a length of 150mm for 69,75 Euro +VAT and the DEF103 in the same format for 78,10 Euros +VAT per piece when I take 4 of them.
The 103s need forced cooling so I only take the 26s into concern.
Anybody interested in the same types so that we can ask for reduction?
Some other thoughts about heatsinks:
Take a 10mm base plate aluminium (300mm x 150mm = 0,045 m²)
Bolt 10 pieces of 80 x 20 rectangular profile (150mm long) on it.
Insert a piece of steel (100mm 15x15mm²) into the fins (profiles) to ensure a more equal pressure distribution between base plate and fins.
Anodisze it.
Prices?
Baseplate: 0,045 x 275 Euro = 12,37
Fins: 1,5 meters a 9,80 Euro = 14,7
Screws: 20 x 0,25 = 5 Euro
Steel: 10 x 100mm = 1m x 13 Euro
Anodizing: ? (I just check)
That sums up to 45 Euro, without anodizing, sawing and drilling. Sounds not worth it.
What do you think?
Cheers
Thomas |
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| byteboy |
More (most?) important:
What Rth do you think you can achieve this way? :)
I think DIYing heatsinks only works if you want to spend a lot of time, have the right tools and are able to get the Al for free or very cheap.
Just my opinion. |
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| threefff |
Hi Byteboy,
no idea with what Rth I would end up with this construction. I assume, it should not be too far from 0,25 K/W.
But all in all I agree with you: When the alu is for free it is worth it building heatsinks yourself. If not, it's not.
Leaves me with the old problem....
Thomas |
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| jacco vermeulen |
It is, it is !
I built heatsinks like that myself, both welded and tapped.
The alloy can be bought for scratch at salvage yards.
The downside is that if you count your hours diy heatsinks become very expensive.
I did it in my student days, even built a 36 foot sailing yacht in those days.
Now, my time is precious, i can make more money in other ways than saving some with hard labor on heatsinks. |
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| byteboy |
The IMHO way to go (If you cannot get a group buy organized for a good price :( ) is to try and get them second hand, from scrapped equipment, surplus shops, eBay etc.
This usually takes time and it can be difficult to find the heatsinks that you like and suit the job (and your wallet ;) ), but it is possible to find them.
It sure can be a lot cheaper than buying new ones.
Same goes for power caps and transformers.
If you don't want to or cannot wait you will have to pay the price I'm afraid..... |
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| threefff |
hi jacco,
yes, time is precious, that's true anyway. But for DIY you need to spend some...
I better do not report, what I built in my student days, although a sailing boat was only under consideration, not more.
Hey byteboy,
I searched the web (and this forum) for almost the last six month and did not find surplus or used heatsinks of the desired format. Maybe I'm not flexible enough with the size and optics.
The best offer I found 'til today are these deltour DEF26 heatsinks mentioned earlier in this thread:
They offered me:
Prices for larger quantities DEF26/150/zw:
Price/piece delivery qt 10 pieces: Euro 64.20
Price/piece delivery qt 20 pieces: Euro 58.60
Price/piece delivery qt 50 pieces: Euro 50.15
And for large quantities only they offered me the DEF123, they don't have pressed in fins, but are extruded as the whole piece (R-th like the 26s).
DEF123/150/zw
Price/piece delivery qt 50 pieces: Euro 42.25
All prices are ex VAT and shipping (remember: size is 300 x 150 mm², fins parallel to the 150mm).
Any better suggestions?
As I need 4, who would take some others?
so long
Thomas |
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| illusionxx |
Hello everybody,
i´ve asked for a quote for the Fischer & Tausche high quality caps.
It is 23,33 EURO/pc for 47000uF 63V if we take 100pcs.
To all who are new to this thread:
The Fischer&Tausche caps are the same as Thel and Mundorf
which are all produced by Krummer (Serie 901).
The specs are:
D=91mm; h=70mm
L= 12nH; tan-d = 0,22
ESR typ = 0,005 Ohm
Ripplecurrent = 100A
Temperature: -40 bis +85°
Lifetime +40° = >540.000 h
Lifetime +85° = >20.000 h
The caps are really cheap compared to about 70 Euro/pc at Thel or Mundorf and even better than the RIFA caps. Simply the best quality one can get.
If there is enough interest in these caps i could offer a groupbuy.
Tell me what you think,
illusionxx. |
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