'Perceive v2.0' Construction Diary

Status
Not open for further replies.
Jump to Latest
#681
jleaman said:
It's a sad day today.. I found out you'r going to power these very nice speakers with gain clones 🙁 :bawling: :bawling: :bawling: :bawling:
Click to expand...

Don't be sad 😀

DIY-wise I've had ESP P101, AKSA 55N+, Hypex UcD700AD(loaned), GB150 and GB300. When I listened to the GC's they had a brand of sound that I hadn't heard from those.

Its all about refining it down to what works for you. I mainly just like hearing and building different designs, each has a set of strengths that are subtly different to the rest. I've never had what I'd call a bad sounding amp just different degree's of good. Perhaps the weakest was the ESP P101 and then the UcD700AD but still nice sounding amps.

Commercial stuff is fun too but spendy. I've had a Roksan Kandy mk3 for awhile now and I like it but most of the DIY stuff I've built sounds better. The Chord is in a class above the best DIY I've tried for now but then again it did cost a lot more, so value for money wise its pretty poor.

ESP101:
An externally hosted image should be here but it was not working when we last tested it.


AKSA 55N+:
An externally hosted image should be here but it was not working when we last tested it.


GB150's:
An externally hosted image should be here but it was not working when we last tested it.


GB300's:
An externally hosted image should be here but it was not working when we last tested it.
 
#682
Vikash said:
R2 looks fine. R1 simply needs jumpering if you're skipping series resistor on the input. Confirm with Peter, he's very helpful.

Diodes are fine. They were designed at different times and slight changed between versions. You'ev got the back of the diodes facing line which is correct.

Tapping is easy if you have a drill press. I drill the pilot hole, then put the tap into the chuck and wind it manually (I use some Rocol cutting compound here). The press ensures that it goes in perfectly straight and turning the chuck manually gives you enough feel to not over do it. In fact I now just put the belt pulleys on the least torque setting and power it on a second at a time. Tapping is a breeze this way.

I believe Peter uses a hand gun with a clutch which works well for him. There is a wealth of info in this thread when I was first going through it all: http://www.diyaudio.com/forums/showthread.php?s=&threadid=38200&highlight=

I use a cheap blade from ebay which is designed for cutting non-porous metals (don't use anything else!). It has a negative rake, 80 teeth and is about £14. You can get a proper Freud one etc for triple or more the cost but it will probably last you longer too.

4mm thickness should be no problem (again get some Rocol cutting compound to help here) and use multiple passes for anything thicker. I did 10mm ridge in some heatsinks earlier today using this method.

Obviously be careful and well protected when cutting metal. It requires more attention than woodwork because when things go wrong you can lose body parts!
Click to expand...

Sweet, top man Vikash. Just what I wanted to hear (except for the bit about losing body parts).
 
#683
ShinOBIWAN said:


Don't be sad 😀

DIY-wise I've had ESP P101, AKSA 55N+, Hypex UcD700AD(loaned), GB150 and GB300. When I listened to the GC's they had a brand of sound that I hadn't heard from those.

Its all about refining it down to what works for you. I mainly just like hearing and building different designs, each has a set of strengths that are subtly different to the rest. I've never had what I'd call a bad sounding amp just different degree's of good. Perhaps the weakest was the ESP P101 and then the UcD700AD but still nice sounding amps.

Commercial stuff is fun too but spendy. I've had a Roksan Kandy mk3 for awhile now and I like it but most of the DIY stuff I've built sounds better. The Chord is in a class above the best DIY I've tried for now but then again it did cost a lot more, so value for money wise its pretty poor.
Click to expand...

Exactly..

Its VERY rare when you come across an amplifier that sounds substantially BETTER compared to a good amplifer.

On less rare an occasion (though still quite rare) you do come across something that sounds substantially DIFFERENT - yet not symbolizing something altogether BETTER.

That then leaves you with numerous good amplifiers that offer subtle yet distinct differences.

Any substantial difference these amplifers provide are largely due to differences in power supply design and source/preamp quality/interaction with the amplifier. Some of the more subtle yet distinct differences have to due with parts quality, AND the resonance control of parts in general.

From what I gather substantially better sound can be afforded a gainclone via:

1. A MUCH better powersupply (no surpise there), and
2. A buffered input with reduced gain for the chip amp - particularly with better tubes for the buffered input.

In the gc's case it might be interesting to see which of the two was more important to sound quality - and its likely that member NUUK could elaborate on this.
 
#685
thylantyr said:
I'd be driving those speakers with six QSC PLX3402 amplifiers,
each in bridged mode, one per driver. Says 'no' to low powered amps 😎 :devilr: 😎
Click to expand...

We all know a half kilowatt into a tweeter is a poor show for you. 😀

The room is small and the Perceives have decent a 94dB efficiency from 400hz up. The bass driver is hungry at only 85dB though. I don't listen at high SPL's so those kw's would be wasted on me, I agree that headroom is cool though.
 
#686
ScottG said:

From what I gather substantially better sound can be afforded a gainclone via:

1. A MUCH better powersupply (no surpise there), and
2. A buffered input with reduced gain for the chip amp - particularly with better tubes for the buffered input.

In the gc's case it might be interesting to see which of the two was more important to sound quality - and its likely that member NUUK could elaborate on this.
Click to expand...

Hi Scott,

I'll be following Peter's recipe from the Patek SE:

http://www.6moons.com/audioreviews/audiosector/patek.html

I too was a little concerned with the PSU but Peter assures us that the his LM3875 flavour is best with 1000uf Blackgate STD per rail and 100uf Blackgate N as the coupling caps. I can always whack on one of the BMM supplies that are in the photo's above. With over 80,000uf resevoir and CRC filtering it should make a good comparison between a low ripple well regulated supply and a somewhat bare supply.

Peter also suggested tailoring each amp for its given duty. For the treble, don't bother with the 1000uf Blackgate STD's and just use the 100uf N types. Since the gainclones are so simple I'm looking forward to just playing around with components, snubbers and checking the differences in sound(if any).

Have you messed around any with GC's?
 
#687
Vik, can I use my mitre saw for cutting the alu?

Its this one:

0601B22541.jpg


I've also got a table saw but its pretty useless for accurate, repeatable cuts. The mitre on the other hand is very accurate.

The bore size is 30mm on the mitre. Is it even possible to get a 10" metal cutting blade for this? I can't see anything on ebay or the few sites I've checked out. Perhaps there's a good reason for this?
 
#690
lufbramatt said:
check out the last blade on this page:
http://www.toolstation.com/shop/Blades/CircularSawBlades/d120/sd2586

looks to be what u'd need, £60 tho!


edit: there seems to be some suitable blades on this page too: http://www.toolstation.com/shop/Blades/IrwinSawBlades/d120/sd2865
Click to expand...

Cheers Matt.

The 60 quid is a kick in the nuts though. I could have the stuff proffessionally cut for that and I've got to ask myself just how many times will I be cutting aluminium? Not many is my guess.

Vikash got my hopes up with his £15 special from ebay but I can't seem to find anything similar.

I fancy cutting all the metal myself so will end up buying a blade but I really can't stomach £60 just yet.
 
#695
In fact, I've just noticed that Toolstation sell the same one for £15 on the link by lufbramatt. Also there are some freud blades going on ebay from U.S sellers for dirt cheap ($40). Didn't check them out properly to see if they're negative rake (for alu etc), but check them out for a potential bargain.
 
#696
ShinOBIWAN said:


Hi Scott,

I'll be following Peter's recipe from the Patek SE:

http://www.6moons.com/audioreviews/audiosector/patek.html

I too was a little concerned with the PSU but Peter assures us that the his LM3875 flavour is best with 1000uf Blackgate STD per rail and 100uf Blackgate N as the coupling caps. I can always whack on one of the BMM supplies that are in the photo's above. With over 80,000uf resevoir and CRC filtering it should make a good comparison between a low ripple well regulated supply and a somewhat bare supply.

Peter also suggested tailoring each amp for its given duty. For the treble, don't bother with the 1000uf Blackgate STD's and just use the 100uf N types. Since the gainclones are so simple I'm looking forward to just playing around with components, snubbers and checking the differences in sound(if any).

Have you messed around any with GC's?
Click to expand...

Ola!

I haven't, but I have been looking at them long and hard for a somewhat different mode of operation (i.e. current/voltage mode while allowing a degree of voltage/gain adjustment) - at some point I'll likely experiment with that (..and with tube buffering well beyond the ordinary).

Remember when it comes to power supplies Peter's implementation - while heavily "tweaked" allowing for subtle but distinct perfomance gains for a given application, does not compare to other more substantial means of improving the power supply. Notably meeting current demands without out large value caps, or "simply" rejecting current "looping" within the power supply. (..achieveing either can be quite complex however.)

At a minimum I would consider an appropriate choke just past the rectification for the typical "choke loaded input" configuration - that usually helps things considerably with little or no penalty beyond cost.

Alternativly you could go the route of Nuuk and try out one of his switching power supplies (if he still has some available).

http://myweb.tiscali.co.uk/nuukspot/decdun/gainclonesmps.html

Either method for subjective testing purposes (i.e. one amp only), could provide a rather large gain in sound quality that could then be replicated for the rest of the amps IF you decide its worth the additional cost. Then of course there are methods like the use of member Gary P's constant current sources that could well provide very substantial gains in sound quality provided the current matches the maximum rating for the given chip.

(note: if you decide to go the route of choke-loading, then try asking for help on the power supply forum here.. or perhaps the chip-amp forum, but I don't remember choke loaded ps's mentioned there.)

If you stick with the "bare" route then consider using a balanced transformer for mains conditioning (..but its not cheap though). An even better but more costly alternative here is completely re-generating your mains with an AC/DC power supply/battery/ DC/AC power inverter (..capable of providing a large amount of current). (..and sometimes you will see this solution being used at some of the better sounding "rooms" at HiFi shows.)

Of course the nice thing here is that lots of "tweaking" is available, and at varying levels of user-ability/complexity and cost. And I do think that Peter's suggestions make for a very good start. 😉
 
#697
Thanks Scott, I'll see what they sound like as is and then consider stuff like you've outlined.

Vik:

How did you achieve the brushed look, I had a go on one the pieces of alu last night and it looked aweful. I did do it free hand so I guess my technique is poor or theres a better way?
 
#698
the last lot of aluminium angle (1" angle about 3mm thick) I cut was done with a mitre saw, I used the cheap screwfix 40tooth blade that I has in there (they were £3.45ea on special when they were clearing stock) and went slowly/carefully, they came out suprisingly well.
 
Status
Not open for further replies.
Top Bottom