DIY amp kits

[grubyhalo]

Thanks much for your input, was really helpful.

 

[GeorgeO]

Have you tried Miracle Electronics, in Magadi Road? I have bought toroidals many times from them, and found then very friendly and responsive. Nilesh Shah is the Director in charge. Their website is

-: MIRACLE :-


>I will be able to provide complete circuit kit for Pass Labs DIY First Watt >Clones.
>Kits are with PCB and Parts only

No Transformer, no Cabinets. I am too having difficulty in sourcing toro transformer and good quality cabinet enclosures.
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[sasmit]

I can supply you with AVEL LindBerg toroids, LM4780 Paralell Kits..my own design..I have posted in the forum you can see that.

I can also supply
---------------
1. WIMA caps
2. Panasonic FC series caps
3. Metal film resistors ( Vishay or Tyco make )
4. low value , high wattage tolerance like 0.1 ohms 1% 5W
5. National LM series IC's ( LM 3886 , LM 4780 ) etc.
6. I have readily available the LM4780 Paralell kit which I have posted here also
7. Toroid transformers ...
8. Hard to find transistors , mosfets.

 

[sasmit]

Thanks for your insight cranky. Is there any trade-off at all if I use an EI core in place of a toroid in the power amp? Also, would there be any trade-offs if I go for an EI core for a tube pre-amp or a DAC?

An EI core ..albeit the stacked type ( Primary is on top of secondary) are much better than toroids. Even an ordinary EI core with good quality CRNGO core tightly packed is pretty good.

The toroid's advantage lies in its low flux leakage and size, infact it is more prone to noise from mains and DC component in AC line. So if you are putting the transformer in a separate case or far away from the amp an EI si fine , if you have space constraint use an toroid..

 

[grubyhalo]

An EI core ..albeit the stacked type ( Primary is on top of secondary) are much better than toroids. Even an ordinary EI core with good quality CRNGO core tightly packed is pretty good.

The toroid's advantage lies in its low flux leakage and size, infact it is more prone to noise from mains and DC component in AC line. So if you are putting the transformer in a separate case or far away from the amp an EI si fine , if you have space constraint use an toroid..

Thanks for your input. I foresee requirement for both EI and toroid in my future. I will get in touch with you in time. Thanks.

 

[square_wave]

deleted post

 

[soundsgreat]

Hi,

Wow So many replies and not one person bothered to show some compassion towards me for the said incident :sad: !! Talk about forum unity !!

Well at first I was not interested in posting anything on that particular event,but when someone mentioned the name of that company I couldn't help myself but to post ! thought after reading that some folks will show some courtesy and such (although never was looking for any in the any case )

Even now I was hesitant to post this,but I was upset that in an other thread some one posts similar (not same mind you,no one physically assaulted no one there ) and we have the entire forum going all over the place to help and show compassion (I have nothing against anyone here don't mistake or confuse) !! and here I am not getting a single post in reply :indifferent14:!!

Well whatever,Am here for a different reason not for any artificial fame or to be a show off, Am not a person with artificial self inflicted ego and such !! so COOL !!

Anyways coming back to the topic !

I can supply you with AVEL LindBerg toroids, LM4780 Paralell Kits..my own design..I have posted in the forum you can see that.

Sasmit no offense but please do post your offering's in this thread and confuse people !! Please start a new thread and post all you want !! I myself Am interested in some LM stuff so will surely respond to you there !!


George Miracle is good no doubt but not always as helpful and ready to take small orders !! I don't know the person you are referring and have contacted them several times without much of a good result !!

I run huge capacitor banks, 40,000uF per channel, and the inrush current is totally under control. A toroid with the same kind of bank would blow the fuses.

If you look at Peter Daniel's DAC, he still uses an EI there

Cranky could you kindly recheck the facts ??

Regards.

 

[grubyhalo]

I just placed an order for a full kit of F5 parts (just the power amp bits, no supply, heatsinks or hardware) at Tech-DIY.com, Jack runs a nice service. The cost is only marginally more than a custom selection at Digikey, and both contain comparable parts but Jack provides the input FETs which are near-impossible to get as they're out of current production. The total is $82 with shipping, which should be under the $100 limit for customs...

Was just checking it out myself. Please let me know how much the customs duty comes up to. Also, do you have any source for heat sinks?

 

[GeorgeO]

>George Miracle is good no doubt but not always as helpful and ready to take >small orders !! I don't know the person you are referring and have contacted >them several times without much of a good result !!

I have always ordered a single toroidal at a time-never more, except a single time when I built my AKSA as a dual monoblock. From my own experience I will not hesitate to buy from htem again.

Re the full kit-I bought an AKSA 55N a few years ago, but sourced the chassis and trannies ( cheaper, lighter to ship). I asked Hugh Dean to send the kit, incl heatsink( I think any decent aluminium extrusion will do the trick) to the US since I was going there and I bought it back wth me. Even my Peter Daniel NOS DAC was without enclosure or transformer, I got a small tranny from Miracle. I picked up he premium model and found Peter to be very responsive and courteous to all queries.

 

[grubyhalo]

...
@grubyhalo: Vega electronics in Mumbai had some nice 2c/w/6inch heatsinks available for sale. For the 0.3 C/W rating of the Pass F5 in stereo mode, you would need about 24 inches of heatsink total, or two 12-inch sections, one for each channel. They also have a nice book from which you can choose a design and they will give you a custom length. The cheaper heatsinks are also available, but those are ~3c/w/5 inch (empirically calculated, not data-related), and require one 10-inch section for *each* transistor, so total of four 10-inch sections, and you will still need to back the bias down a bit, to the 1A range to stay safe. In any case I intend to use lower bias till winters are here, and then crank it up for full performance.

I intend to use custom transformers, dual 18V secondaries at 10A continuous rating. I already have such transformers but they are 22V secondaries (ergo, 31VDC), and not suitable for the F5.

Is there an online catalogue of the brand of heatsinks they carry from which one could choose? Do they usually accept orders over the phone or email? I think this might be their address though am not able to pull an email id. or website for them...

 

[grubyhalo]

Sorry, wouldn't know about that but probably not... they seem to be a small shop but used to operate a kit business so they might be still having some arrangement to conduct long-distance business. There might be some phone number you can call and ask about, but maybe it'd be more helpful to get a Mumbai member to check on it for you.

The people you got the address for aren't the same ones. Try this one instead:

Vegakitindia.com - Suppliers of Hobby Kits, Robotics, Electronic Parts and Musical Kits

Thanks, that sure does help. I'll try contacting them on their email and see what happens.

 

[soundsgreat]

Hi,

@soundsgreat: which facts? The UI core used in the Hammond 229D16 in the PD DAC is no different from an EI core transformer as far as construction goes. It is mere semantics, both are bobbin-wound and are not directly wound on the core like a toroid. It behaves exactly the same way and the core loss calculations and flux density would be identical to an EI of the same volume

The Fact that its not a regular E&I based tranny !! Its a type of transformer called "Spitcore" or something close "C" Core (or as you say an U&I ) transformer which is more of a mixture of C core and Toroid then the E&I as you mention !!

The transformer is done to take the advantages of both C Core ( Perhaps to some extent even E&I ) and Toroid ! From the Hammond number that you posted its very clear if you check the spec or the features its mentioned that it is infact a mixture of C and Toroid or as they call it "SEMI TOROID"

Hammnod Transformer details

Now check the details of the "C", and pics here

This is a typical "C" Core transformer !

This is typical U & I

Now ironically although you have identified the core correctly you have missed the origin !! The U&I core has more similarities to "C" Core the E&I as you mention !

This is a exert from a manufacturer of U&I bout the technology !

UF-core and UI-core, these Soft ferrite shapes are available in lamination materials (for stacking), powdered material (typically powdered iron), and ferrite materials. In laminated form, features of UF cores and UI cores are similar to that of the "C" core, and can take full advantage of grain orientation

since you're keen to be exact (EI is a more easily understood term) we'll call them bobbin transformers for exactness and confuse newbies who will wonder what this new animal is.

Am just trying to get the thing right, thats all ! and on contrary to what you say Am trying not to confuse newbies and others but to show them whats what,with the above I think I have made my point clear !!

I'm not sure why you've quoted the other part of my post. A 1A fast-acting fuse required for a 220 VA transformer running at 230V will blow at the inrush current of a 40,000uF cap bank on the secondaries of a toroid transformer. There's no point is using higher rated fuses as it defeats the purpose of a fuse. Since you have quoted it without context, can you please specify where you think I have made an error and I will be glad to illustrate this with the numbers and fuse specifications as well.

In theory what you say might be correct ! but sometimes its not necessary to have it that way !! Also as you say its not waste or does not defeat the purpose of the fuse if it exceeds the theoretical value !

The Typical example is Odyssey Startos ! Now we all know that it doesn't blow fuse each time we switch and it has a toroid transformer for the supply and some of you must also know that the stock version comes with 60,000uF cap bank and extremes with 120 !! Now if you look the at the fuse spec you'll know the point Am trying to make !

Stratos Stereo:
base model specifications:

* $1,195 USD
* 2 x 150 Watts RMS @ 8 Ohms
* 2 Ohm load stable
* Class A/AB
* 2 - 400,000 Hz frequency range
* 60,000F memory
* 45 amps current delivery
* <0.04% THD (not audible)
* >500 continuous damping factor
* Input impedance 22K ohms
* DC offset <1 mV
* RCA & XLR (bridged) inputs
* 400 VA Plitron transformer
* Sanken Epitaxial Planar Transistors 2SA1216 & 2SC2922
* Anti vibration dual thickness PCB
* Power consumption when idle 30Watts
* 4 internal fuses 250V/6.3A, 5x20mm, fast blow
* Additional electrical protection fuse
* 54 lbs weight / 24.5 kg
* Dimensions: 19 width x 18 deep x 7 height (in) /
48.3 width x 45.7 deep x 17.8 height (cm)

Thats all I have to say !

Regards.

 

[soundsgreat]

Hi,

It would be foolhardy to start making examples of an amplifier whose topology and design are unknown to us. Quoting from a spec sheet to prove technical points is risky without having all the relevant details backed up.

Very well ok fine if you think its foolhardy (and indirectly trying to call me one ) so be it I have no probs !

I am not in a mood to get into a protracted confrontation with you on this topic, it has been significantly sidetracked already. I will now reply only to on-topic posts, as the TS must be frustrated at his simple question being moved so far away from a reasonable answer.

Am in no better mood then you on this ! so although I would've answered the questions raised by you in point wise manner,but it so seems that its of no use,anyways you'll not accept what I say !! its very very apparent from this thread and some others aswell !!

You have a nice day too....

Regards.

 

[aks07]

Regarding that Stratos amp spec it would be helpful to know the following
1. Placement of the fuse(s).
2. Is there a delay circuit?
3. Does it have some sort of regulated PSU?

Ofcource fusing rating itself is a function of input voltage and load wattage.


BTW that Anaconda looks awesome! Your projects are so inspiring.

 

[grubyhalo]

...
@Greenie; Check Greg Ball's design. May be what you're looking for, as it is complete. The Aksa or the F5 may be sonically better, but the GBA-150 is very easy to set up as no further purchases (apart from tools and wire) are necessary and Greg's support is first-rate. The amp is moddable (with a new supply and heatsinks) to 50 watt Class A operation, though most everyone claims there is very little difference caused by doing this.

I'm guessing I'm greenie. I'll sure try reading up on the GBA, sounds pretty promising. As things stand, I'm trying to see if I can get someone to build the F5 for me for a fee. I've been reading up a bit on the F5 and am quite enamored by it and would love to have one built. If in case I'm not able to get it built, I guess the best option for me would be to go the GBA way and try solder-slinging on my own.

 

[soundsgreat]

Hi,

BTW that Anaconda looks awesome! Your projects are so inspiring.

Thanks for the kind words ! Going by your posts I recon you are no amateur either hyeah:!! very apparent from your intro post to the last post in the DIY Tube Amp post,So it feels good to be acknowledged !

As things stand, I'm trying to see if I can get someone to build the F5 for me for a fee. I've been reading up a bit on the F5 and am quite enamored by it and would love to have one built.

Gruby I would be more then happy to build you the F5, fee or no fee I don't care !! Since you plan to buy it from Sudhi,I can collect it here locally and build it for you !!

You may contact me on my mail (you have my ID ) and let me know as to what type of components you prefer and what PS Unit etc etc etc ! Also your preferred cabinet design and such !!

Regards.

 

[grubyhalo]

Hi,



Gruby I would be more then happy to build you the F5, fee or no fee I don't care !! Since you plan to buy it from Sudhi,I can collect it here locally and build it for you !!

You may contact me on my mail (you have my ID ) and let me know as to what type of components you prefer and what PS Unit etc etc etc ! Also your preferred cabinet design and such !!

Regards.

Wow, cool man! That's really something. Let me just finalize my driver choices for the speaker design I have in mind and I shall let you know.

P.S: I'm not going to let you build it for free.

 

[soundsgreat]

Hi,

Wow, cool man! That's really something. Let me just finalize my driver choices for the speaker design I have in mind and I shall let you know.

P.S: I'm not going to let you build it for free.

No buddy its really nothing,I mean no big deal ! please take your time and let me know !

The idea of me doing is for the fun of building it and helping a fellow Audio Buff hyeah: ! So its not at all bout the money or such ! anyways don't worry bout all that now ! first we shall hammer out all the details of the build then we can come to this part !!

Regards.

 

[greenhorn]

I'm guessing I'm greenie.

*Cough* *Cough*

I really don't mind. I really dont get much time to do this stuff nowadays, and Once I start hypothesizing things (like this one) I really don't get onto the hardware aspect unless its really feasible ( and I can get myself off my lazy bottom). Any Offtopic like this is just an added bonus.

So far I've made only chip amps ( the really cheap ones - LA4440 and STK based ones while in college ) and wanted to move onto something better. I'm not sure if my speakers are ready for class A type quality - or me for that matter. And ordering from abroad - or elsewhere in india is still something I'm yet to learn. I usually get my friends to help out with such stuff.
That a well made EI transformer should be good enough is very good news - most of my existing amps have used PSU's in seperate enclosures - space is not a problem for me - cost is . I guess I can continue with that then

Thanks for all the inputs, and please do continue with the OT :cheers:

And for the record, I'm looking for something as south of 10K INR as possible

 

[keith_correa]

The Pass F5 ~10K for sure. The kit is 82 dollars, the transformers (first quote) 1K each, 16 caps @ ~70 bucks each, and 4 heatsinks at 250 each. I'm waiting on the parts from Jack, and I need to order the transformers once I get the amps set up and running. Don't have the heatsinks yet either, those should be in Tuesday.

Cranky, after/during your build, if possible, can you post logical step wise photos/instructions on your build ala your Usher mod? By this, I for one would know what "building" an F5 would mean/involve and I'm sure there would be plenty of others here equally curious/inquisitive.