Lifeless nonivolving lm3875 gainclone ?

[sinski]

Hi,
Few days ago i finished my gc. It is just very good 300va/25v transformer and premium kit from Peter Daniel without any changes (no zobel, no input caps). It is just experimental design, so i can play with some components and later put it in one nice case:

http://s7.photobucket.com/albums/y25...prototype1.jpg

On the photo you can see one zobel netwoerk, but without zobel the sound is more direct, so now the amp is without zobel.

I was taking care when i was building it. First all components and pcbs where cleaned very carefully, than i soldered all compnents one by one using WBT solder with 5% silver. All cables are from Kimber and input cables are teflon isolated Chord. All inputs and outputs are very good quality.

Actuall the amp sounds very good, but ...

The sound is not involving and lifeless and the bass is not very good.

I compared it to Musical Fidelity A1, Naim Nait 2, Naim Nac72/140. All those amps have less resolution and are not so exact as gc, but they have just punch, prat and strong living involving sound and basslines are much better.

Is there any help possible, or gc ist juts like this ? Do i have to wait longer, so the amp will really run in ?

Any ideas ?

[filholder]

Hi,

I had the same issue, using a Lm based chipamp with a passive preamp. ie just a pot. Really in my and a lot of otehr people opinion these amps sound better when fed through either a buffer or a preamp. There are many people on this site bteer equiped to tell you why however all i can say is to get the best from mine I first tried a buffer and then later a AD815 based preamp. Both helped a lot though i prefer the later.

Here is Nuuks guide to building a buffer:-

http://myweb.tiscali.co.uk/nuukspot/...nclonepre.html

And here is the thread for the preamp i built:-

(re)searching for a better preamp

With soem kind of active stage these amps really fly, they gain the punch that they are lacking without IMHO.

Phil

[peranders]

Originally posted by sinski
Is there any help possible, or gc ist juts like this ? Do i have to wait longer, so the amp will really run in ?
Any ideas ?

Let a friend do the connecting and you must tell which amp you are listening to. Make it 5-10 tries and then see if you can pick the Gainclone. It's a big difference if you can see and know what you are listening to.

[lndm]

I used to use LM3886's and I found they give a very straight performance. They are fairly accurate but lacking flavour IMO. I guess you could make them sound warmer, or anything else you wanted by using a 'colourful' pre stage. I guess I could say that the 3886's are 'open to suggestion' - and suggest you should!

[Garnett]

Hi Sinski. I am building the very same kit! I'm interested in the replies you get, because I was worried what I understand may be more defined bass may well also mean quieter bass.

I'm loathe to start work on a second DIY project straight after my first so I guess I'll have to wait and see. In the meantime can you post any more pics? They are really useful for a fellow builder who is very new to Gaincloning.

Would a snubberised power supply help? Perhaps someone else with more knowledge could advise.

In an effort to be helpful, I tried to do a search for relevant threads (Anyone got any good tips on how to search on here? - I certainly haven't found the knack yet).

Anyway I found this post and there are some potentially useful replies.
http://www.diyaudio.com/forums/showt...345#post144345

[jimbo1968]

I think you can limit google searches to a particular website, but then why do that? Just google it straight.

[sinski]

I was testing gc with different sources. I have two sources -DPA Drive+DAC DX32+passive preamp with 50k blue alps and the variable output of my Benchmark DAC1.

Yesterday o took my gc to my friend and we have tested it with Naim cd3, sony XA30es and DAC1.

The effect was always very similar and the worst was to compare to my old Nait 2 with all tweaks from www.acoustica.org.uk

Nait 2 is just dancing and sparkling with music and gc is very exact, but absolutely lazy and sleepy. Maybe i will try snubber ps.

[Nordic]

As it has been said before, I'll just repeat it, get an active pre or valve buffer. Maybe google Decibel dungeon and play around with some of the implementations on there

[sinski]

Benchmark DAC1 has one active buffer build around ne5532A and a variable output. Connected directly to Naim Nap140, Crimson 620 and Krell 50 (three different power amplifier) sounds very good. Connected to gc is lifeless.

[rudi]

Originally posted by sinski
Benchmark DAC1 has one active buffer build around ne5532A and a variable output. Connected directly to Naim Nap140, Crimson 620 and Krell 50 (three different power amplifier) sounds very good. Connected to gc is lifeless.

there is some of your problem
the benchmark DAC1 is a fine DAC but lifeless to start off with. it is very good for recording equipment but does not have the musicallity. then the second problem is the NE5532 .... it isn't very good , you can replace it with a better AD or BB substitute.

have a look at Russ Whites's freebird. it will give it exactly what you are looking for