[kaushama]

Heed canamp has won the hearts of many headfiers. It is becoming one of best value for money home SS amps. It even trounces the goodness of Music fidelity V3 which belongs to tube sector.
Its simplicity in circuit topology always fascinating! (classA)

I was one of the first who imagined the potential of modding the amp as it uses, non-audiophile components and a power supply, which has lot of potential for improvement (snubberized Power supply) not to mention the OP Amp Rolling!


http://www.head-fi.org/forums/showpo...&postcount=289
http://www.head-fi.org/forums/showpo...&postcount=293
http://www.head-fi.org/forums/showpo...&postcount=295

But then this post by Banfi T emphasized the need of synergy between components and originality of layout.
Quote:

Heed audio has gathered many experience in the field of audio engineering, I know some of their theories. Basically, there is a *very* high chance that with modding you would null this knowledge built in their product not knowing the reasons for a particular solution.

http://www.head-fi.org/forums/showpost.php?p=2482767&postcount=301

Though I have seen many attempts at modding this wonderful amp after, I do not know how much of objective improvements have been achieved by the modifiers!

http://www.head-fi.org/forums/showpo...postcount=1065
http://www.head-fi.org/forums/showpo...postcount=1097
Heed CanAmp mods.

The last link shows PINKFLOYDS experience and ideas about the subject. It's a pity we do not have him here now as he is one of the pioneer members, who modded the can amp first

[size=medium]So can it be really modded to have improvement in SQ? Do they give moddifiers just placebo pleasure?[/size]

As The theory in electronics can be quite different from the results we need a database of user experience and views of the PRO's who modded the canamp. so post your views and Mods here for the benefit of everyone!!!

 

[kaushama]

mrarroyo! Do you really think Mods work? Do you know most cost-effective and most important Mods if there are any?
I wish we had PinkFloyd's opinion here!

 

[kaushama]

Some of the potential Mods!!

A. Better ESR electrolytics in place of the jamicons in power supply
B. 35v 100uF better ZA ultra low impedance caps
c. power resistors replacement
D. diodes replacement with ultrafast ones
E. opamp socketed for rolling
F. Better connecting wires (Silver?)

 

[mrarroyo]

Well you could start by putting a socket to roll op-amps, like:

2 x 16V 4700uF general purpose Jamicon capacitors are fitted as stock. First in were a pair of el cheapo Suntan 105C 35V 10,000uF. You can also swap out the 2 x 100uF stock Jamicons for a couple of 35V 100uF ELNA Cerafines. Finally add the UF4007 ultra fast diodes.

You can also put heat sinks at the various sources, such as:

I should point these are not my mods, I am contemplating doing them. I stole the ideas from Great Britain (PF), hope they help.

 

[d-cee]

Quote:

Originally Posted by kaushama /img/forum/go_quote.gif Some of the potential Mods!! A. Better ESR electrolytics in place of the jamicons in power supply B. 35v 100uF better ZA ultra low impedance caps c. power resistors replacement D. diodes replacement with ultrafast ones E. opamp socketed for rolling F. Better connecting wires (Silver?)

hehe those are the mods i did to my canamp (as inspired by pink floyd)

as seen here: http://a-chau.net/gallery2/v/mambo-articles/canamp/

opamp socket for easy opamp rolling + better hookup wire and you can sort of see the sprague power resistors

ultrafast diodes, better caps all round, use evox rifa (ultra low ESR and ultra long life, rated @ 105 degrees C for the big ones, and nichicon ZAs

replaced the caps at the front with some nichicon muse golds

all film caps moved under the board and replaced with evox rifa polypropylenes

 

[kaushama]

So d-see does it make a difference? A significant one?

 

[Dexdexter]

Here is the resource where much of this is coming from (but you must register there to see it):

CanAmp Mods

 

[yrh0413]

=) all these mods only make me more anxious to get my Heed! Argh, i hate waiting!

By the way sorry to throw out a noob question: Are the RCA connectors at the back and the 1/4" at the front replaceable?

 

[Dexdexter]

Quote:

Originally Posted by yrh0413 /img/forum/go_quote.gif By the way sorry to throw out a noob question: Are the RCA connectors at the back and the 1/4" at the front replaceable?

Sure, if you can solder...they're just parts.

 

[d-cee]

Quote:

Originally Posted by kaushama /img/forum/go_quote.gif So d-see does it make a difference? A significant one?

i can't really say lol, i barely listened to the stock unit before modding the heck out of it. also, i'd say my aural memory is quite unreliable. i do know one thing it sounds damn good!

i remember the unit sounded good out of the box and sounds fantasmagorical now as well. but alas, there is currently only 1 other canamp in Australia, another on its way
Quote:

Originally Posted by yrh0413 /img/forum/go_quote.gif =) all these mods only make me more anxious to get my Heed! Argh, i hate waiting! By the way sorry to throw out a noob question: Are the RCA connectors at the back and the 1/4" at the front replaceable?

pretty sure you'll be blown away with its out of the box (and 3 year waranteed performance)

and yes, i don't see any reason why they couldn't be replaced. the 1/4" headphone socket isn't even board mounted. the RCAs are, but seem like the're conventional size/layout

 

[daggerlee]

Throwing my dog in the ring...sorry for the blurriness.

Not as modded as d-cees...what's been done: bigger caps at power supply, sprague koolohm resistors, DIP socket. Would like to replace the caps up front someday as well.

As to the sound improvement, the biggest (obvious) sound difference is changing the opamp, right now I have a LM4562 in there on a Browndog and don't see it changing anytime soon - very musical opamp, better than the AD823 which I found too shrill/lean with K701.

.I would say the mods are last 5-10% variety, not a HUGE difference...which is why I don't plan to replace the film caps, as they seem to me to be a last 1% mod

.

You can definitely change out the headphone socket, although I don't know to what as you'd have to start hacking at the faceplate if you'd wanted, say, a neutrik locking one to fit. I wouldn't bother changing the RCAs either, as they are quite close together on the backplate, and I doubt you could fit 4 Cardas or whatever together like that.

As a side effect, with bigger power caps and better power resistors, the Heed runs cooler than it did before.

One last thing, if you were to mod it, I would recommend changing the opamp and putting a socket in. Why? At least on my Heed, with the NE I was measuring around 30 mV of DC offset at the headphone jack. Now it is highly recomended to keep DC offset to under 20 mV, although I have heardr anything under 50 mV shouldn't be a problem. Still, with the LM4562 I get under 5 mV of DC offset, even less when I had OPA627's in there...I would do it just for the peace of mind.

 

[kaushama]

Yeah OPAMP rolling would give the most discernible mod I agree. But changing caps with better ones can do wonders. When I first made my home amp based on STK 4291 I used some generic caps Later swapping them gave very big jump in SQ.
The power supply caps and diodes again well known the to change the depth and attack of bass notes. Larger capacitance with fast switching diodes is a must when it comes to audiophile gear.
If someone goes to extremes there is potential for IC regulated power supply with dual toroidal transformer with separated voltage rails.
By the looks of it I think it has a snubberised Power supply. Whether it can be tweaked more is subjected to experiment too. The theories and views regarding power supplies could be found in these excellent links.

Snubberized Power supplies

Snubbers

Solid State Amplifier Supply

 

[kaushama]

But I wonder whether sprague koolohm resistor would give any improvement in SQ than reassurance regarding life span!

 

[kaushama]

New LM4562 seems to be in the class of AD637/627!

 

[cotdt]

other than opamp-rolling (LM4562 is in a class above the rest), the other mods that were suggested are unlikely to make major changes due to the design that was used. better would be to buy another canamp and use them in a balanced configuration. these kinds of amps really benefit from that.