Result from comparision: Classic GC, snuberized GC and ESP101 amp....

[nina]

1). Can the T1 and T2 trans be physically separate trans?

CARLOS: Yes, of course. That's even better.

Carlos,

Say, if I have two center-tabed (18-0-18) transfers and 8 MUR820 diodes, what is the EXACT circuit/wiring PLEASEEEEEEEEEEEE?

Any illustration will be very appreciate & helpful




PS: I always scare when working with PS and will not do something I am not sure of.

 

[Mark25]

..............
PS: I always scare when working with PS and will not do something I am not sure of.

My advice would be to run the solution, whatever it may be, with fuses between the Tr secondaries and the MUR bridge, when you first test the configuration. I managed to blow all my MUR's in my BrainGT kit by following a post on here about using centre tap Tr and the MUR bridge

 

[carlosfm]

Carlos,

Say, if I have two center-tabed (18-0-18) transfers and 8 MUR820 diodes, what is the EXACT circuit/wiring PLEASEEEEEEEEEEEE?

For what, for a regulated PSU?
You should not use those trafos.
You could use the secondaries in series and don't connect the CT wire, but that would give you 36V per trafo, too high.
You could also separate the CT wire in two but that would be a cirurgical method that while easy to do, I don't advise you.
2x18V is low if you want to regulate.
So... if you don't want to fiddle too much, keep those MUR860 diodes for another opportunity and this time use 35A bridges.
With those two trafos you can do independent PSUs for each channel.

 

[Vix]

Hey, since it seems that in some cases the "classic" GC was preferred, and it other cases it was the high-cap snubberized version, how about this:

1, GC would be built with small caps (1,000uF) without a snubber, but the PSU would have 10,000 uF caps snubberized, that would be switchable by a heavy duty switch.

So, you could choose the way in which GC would work, depending on a music you plan to listen....

What do you think about this 2 in 1 solution?

Btw, caps would be switched when the power supply is off-no sparks on swiches...

Regards,

Vix

 

[shusha]

In that case better use relays instead of switches. And you might have as many PSU's as you like. It is not a bad idea.

 

[nina]

Re: Re: Re: Re: Result from comparision: Classic GC, snuberized GC and ESP101 amp....

And why didn't you use the recommended 0.1uf on the snubber?
Sounds better.

Just wonder what if we put the big snubberized 10,000 caps on chips -- without additional 100/1000UF on chips (as we are currently do).

Will the result be better?

 

[Vix]

Hi,

Of course relays could be used. At first, 2 in 1 option should be very easy to implement. And we could include the indicator which would tell us whether GC is working in "classic" or "rock" mode.

Including an option with the regulator would be somewhat more complicated, since trafo secondary voltages will need to be increased in order to get approx. the same voltage after regulation.

Add more relays, trannie with more outputs (say, 22+5;x22+5, and there you are....

Regards,

Vix

 

[carlosfm]

Re: Re: Re: Re: Re: Result from comparision: Classic GC, snuberized GC and ESP101 amp....

Just wonder what if we put the big snubberized 10,000 caps on chips -- without additional 100/1000UF on chips (as we are currently do).

Will the result be better?

Hold on your horses...

10,000uf caps are too big to be used on the chips.
You could never get them acceptably close to the chip's PSU pins.
1,000~2,200uf+100nF caps on-board, close to the chips, are fine.

 

[ble0t]

Aren't we getting a tad off topic?

I was hoping for some more opinions that actually involved both of these amps...

There are plenty of other threads discussing the power supply for LM**** chips

 

[carlosfm]

Sorry, you are right.
I just answered a question...

Snubberitis is spreading...

 

[percy]

Results (summary)
-----------------
1. Musicians tend to like the classic 25W GC due to it's close to LIVE music. particularly for the drumer and percussion lovers.

2. Tube lover perfer the sound of classic CG + Fostex 127
3. Most of young pop/rock lover ( <30 year old) perfer Alpha B (either with snubberized CG or ESP101 amp).

4. Difficult to differentiate the Snubberized GC and ESP101 amp in general except with lounder level
5. They can diffirentiate the sound of classic GC and snuberrized one

6. Zen v4 came at the later stage. It sounds much like the Classic CG but slighly more LIVELY

7. Normalized highest scores for amps by type of music:
For vocal music --> Classic CG 25W
For percussion music --> Classic CG 25W
For classic rock/complicated music --> the ESP101 amp
For pop/rock music --> snubberized GC and ESP101 amp


8. Question: If one need to choose one amp back home for their "everyday uses" regardless of speakers, room and type of music. One vote per person:

Rank #1 - ESP101's 30W amp ( 5 out of 8) - "why- as suiatble for most of speakers, ...and most kind of music... most practical for everyday uses"

Rank #2 - Snubberized GC ( 3 out of 8) - "why - I like the bass and its details of mid"
Rank #3 - Classic GC ( 0 out of 8) - "why - Good sounding and close to LIVE MUSIC however it might be for the one who have a special good listening room and good acessaries..... too picky to work with speakers, room and type of music")

Since you are comparing different types of amps (a GC, an SS amp) why not throw in another - a Class D amp like the Hypex UCD or whatever - and see how that comes out ?

 

[loong]

Re: Re: Result from comparision: Classic GC, snuberized GC and ESP101 amp....

Since you are comparing different types of amps (a GC, an SS amp) why not throw in another - a Class D amp like the Hypex UCD or whatever - and see how that comes out ?

I have no plan (and budget) to build a class-D amp Send me one so I can make comparision.

--
BTW, Just share more on my experiment.
I just modified a LM3875 local amp kit using standard components with mostly-based-on-carlos's snubberized PS (Mk II).

Then, I dig out my old 150W amp that sittting idle for many years. It's a kit of STK4048XI with DC servo (attached) using metal film res, Wima and Elna cap. Standard PS (10,000 + 470 + 0.1 per rail).

=STK4048XI vs LM3875 25W=

With my system ( 90 dB speaker and small room), the snuberized 25W LM3875 significantly give cleaner, more details and more muscial for pop, acoustic, classical, vocal & light music and R&B. I also most enjoy listen some Jazz music with the LM3875. However, STK4048XI give more (& deeper) bass on rock & dance music.

=with NADC320BEE =
The result is not much different from the above. STK sound (slightly) sharper. NAD seems to be more friendly than the STK forlong hours of listening. For those we loves rock, dance music or electtronic sound, they might prefer the STK due to deeper bass.

 

[XELB]

Loong, what gain do you have on your STK amp ?
Have you done it with the "non sense" recommended 40dB ?

Have you tried the STK without the inductor in the output ?