Possibility of a group buy of MUR860/MUR1520 and LM338T

[Roushon]

I am going to receive my LM3886 and caps form Apexjr soon. Now I badly need MUR860 (or MUR1520) amd LM338T. You know the feeling of a hobbyist when he just lacks a few components to start/finish.

I started this thread in electronics and parts and nobody seem to bother.

I contacted some distributors and they do not sell less that 50 pieces. And these (or any equivalent) are not available in India. If available then the price is out of my reach.

Now that I have explained my problem in details, someone help me. I need 16 pieces rectifer and 4 pieces regulator. As a second possiblity if someone would like to start a group buy of these I will be the first to join. Please provide some information....

I have deep faith in this forum that I will get help....

Thank you...

[Carondimonio]

Hi all,

I am starting to experiment with the GCs (my goal is to build a 5.1 regulated system, plus a couple of bridged monoblocks), I was also thinking about a group buy of some components.

I asked around and found a good source for the following parts:
LM338T: 2.10 EUR/pc. (for a minimal qty. of 100)
MUR1520: 0.65 EUR/pc. (min. qty 300)
LM3886T: 3.20 EUR/pc. (min. qty 100)

I would personally go for at least 10 3886, 20 338T and 40-50 MUR1520.
If we can put together bigger quantities than the minimal ones, maybe we can also lower the prices a bit.

Any takers?

Cheers,

Bruno

[roibm]

In for some MURs.

[jackinnj]

Originally posted by Carondimonio
Hi all,

I am starting to experiment with the GCs (my goal is to build a 5.1 regulated system, plus a couple of bridged monoblocks), I was also thinking about a group buy of some components.

I asked around and found a good source for the following parts:
LM338T: 2.10 EUR/pc. (for a minimal qty. of 100)
MUR1520: 0.65 EUR/pc. (min. qty 300)
LM3886T: 3.20 EUR/pc. (min. qty 100)

I would personally go for at least 10 3886, 20 338T and 40-50 MUR1520.
If we can put together bigger quantities than the minimal ones, maybe we can also lower the prices a bit.

Any takers?

Cheers,

Bruno

If you are going to the time and expense of building a regulated GC power supply, consider using a discrete design -- it will be cheaper than the LM338T, lower noise, better line rejection etc. and you won't have to deal with the issue of transformers with separate secondary windings. As a matter of fact -- maybe I will make up some discrete regulator boards...

[Carondimonio]

Hi Jack,

well, the separate secondaries are not really an issue, it is very easy to find such toroidals on the market (actually I' m already collecting infos also on this topic).
As for the LM338/discrete issue, well... I do not believe the discrete design would be cheaper and, as I would like to experiment both the unregulated and the regulated solutions, I want to start with a quick-and dirty design.
Actually, if I will like the regulated PS, I believe I will then upgrade to a superreg, but then it will be another story...

Cheers,

Bruno

[jackinnj]

Originally posted by Carondimonio
Hi Jack,

well, the separate secondaries are not really an issue, it is very easy to find such toroidals on the market (actually I' m already collecting infos also on this topic).
As for the LM338/discrete issue, well... I do not believe the discrete design would be cheaper and, as I would like to experiment both the unregulated and the regulated solutions, I want to start with a quick-and dirty design.
Actually, if I will like the regulated PS, I believe I will then upgrade to a superreg, but then it will be another story...

Cheers,

Bruno

The Super-Reg uses a bootstrapped error amplifier -- something which isn't easy to do with a high voltage supply. OTOH, a TL431 reference/error amp in TO-92 costs about $0.30, and a TIP33C about $1.50... despite what others may say, you are pusing the LM338T to the edge of its performance envelope.

At any rate, take heed to mount the LM38T correctly as the tab is connected to Vout -- early in the discussion some people apparently fried the regulator by not looking at the datasheet before installing them.

[ashok]

Hi Roushon,
You better look harder in your market.
I found MUR1560 ( higher voltage ) for R42/- each. I'm sure it is cheaper in Bangalore and Mumbai.
I had bought 2SK1058/J162 in Mumbai a couple of years ago for Rs350/- a pair. They were genuine also.
So look around , you'll find it somewhere.
Have you not seen the posts on LM3886T which say it goes for Rs150/- ?
Stop importing till you are absolutely sure that you can't get it.
I would really like to know how much duty you would have to pay !
Cheers,
Ashok.

[Carondimonio]

Originally posted by jackinnj


The Super-Reg uses a bootstrapped error amplifier -- something which isn't easy to do with a high voltage supply.

I never said it' s easy, but it can be done...

Originally posted by jackinnj


OTOH, a TL431 reference/error amp in TO-92 costs about $0.30, and a TIP33C about $1.50... despite what others may say, you are pusing the LM338T to the edge of its performance envelope.

At any rate, take heed to mount the LM38T correctly as the tab is connected to Vout -- early in the discussion some people apparently fried the regulator by not looking at the datasheet before installing them.

I looked at the datasheet , but thanks a lot anyway for the suggestions, every input is welcome.
As a matter of fact, I do not find the price difference to be so huge (2.1 EUR is approx. $2.65, vs. $1.8-$2 for the discrete version), and the advantage of having only one type of active component on the board evens out the slight price increase...

BTW, I set up a quick Wiki page for the group buy:

Wiki Page

Cheers,

Bruno

[Carondimonio]

Originally posted by ashok
Stop importing till you are absolutely sure that you can't get it.
I would really like to know how much duty you would have to pay !

Just a quick note: as I already did with another group buy I organised previously, I will ship all the parts in small envelopes as "gifts" and declaring a very low value, so that no duties will have to be paid.

Cheers,

Bruno

[ashok]

Hi Bruno,
In India the duties are still unpredictable. Sometimes ( recently ) they let in small packages through with no duty.
The WTO is pushing the Government to reduce import duties. We are going in the direction that will make it very easy to import parts for personal use duty free ( up to a point ). Until we get there we still have problems sometimes.
Another point is that many of our customs officers are Internet savvy ( and connected ) . So you can't push them with gross variations in price. In small packages they probably don't care.

We do have the problem of fake parts. More now than it used to be earlier. So in some cases it might be better to import.
Cheers,
Ashok.