[Help] Vintage preamp worth to buy ?

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Currently in 2011 i'm just entering 'entry level' value bookshelf system to replace my previous pc multimedia system. Due to my tight budget and my passion to get high quality stuff, I have no choice to buy a 2nd hand items or DIY products :D

First start, I have got a DIY bookshelf + aragon2004. When I directly plug my maverick d1 dac into aragon, i find that it's not enjoyable. I borrow my friend's diy preamp with opamp NE532, it totally changes the whole presentation on my system. I think that this preamp is 'just' low end version but it can improve my system, so i think that finding a better preamp is a must.

I read in some posts that aragon2004 will shine when it's matched with tube preamp, but I still don't prefer tube things. When i try to find ss preamp, it's so hard to find a good one as my taste ( clean design,good component,not using to much tiny components).

I end up with several vintage products which is good to my eyes on it's inner design :D but have no opportunity to test it yet. I wish that i could have aragon 24k preamp but never find it's availibity in my city. Now i got a bargain on Preamp Musical Fidelity MVT Class A (not sure it's version yet) with the price around $350

How do you think about this old preamp compared to new product such as rotel with the same price on bnib condition? since I can have an audition on it due to the seller in other city :(

Thanks
 
Musical Fidelity MVT class A Photo - Canuck Audio Mart

Here is the problem with some modern, and all vintage preamps. Modern dacs have more then enough signal output (sometimes double whats needed) to push modern amplifiers into clipping. However a preamp (read preamplifier) will boost the dacs voltage to 10x or more higher. This all came about back when cd players had horrible outputs, and tape and even phone was still being used. So the 150mv signal needed boosted to get to the 1-2 volts need to drive the amp. Alot of modern dacs (yours included) have no problem putting out 2 volts.

I dont see how putting a preamp in between an integrated dac, and an amp. I would try different outputs on the dac since it has volume control and a buffer built in.


Now lets try this. You bypass the volume control on the dac and now the dac puts out the full 2 volts. You then run it into your preamp. at normal listening levels your preamp is going to attenuate 99% of the signal, and then boost what ever is left 10x, then send it to your amp.

If you really think your dac integrated preamp is that bad, your best bet is to bypass the volume control and then use an attenuator and buffer, since you will never need to boost the signal.


After looking at the specs on the maverick d1, something doesnt make sense. It says its inputs are 1 meg, and its output is 5k. That is horrible if its true, and i dont see how its possible. If it is true, then you just need to buy a buffer to turn the 5k out, back into something under 200ohms.
 
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edit on my first post (where is the edit post button?) : since I can't have an audition on it due to the seller in other city, where I live in Jakarta,Indonesia.

@nightanole : to be honest, i'm not too good to understand about the meaning of the numbers that you have mentioned :D I just understand the sound that my system has.

turn the 5k out, back into something under 200ohms
what does it mean? will this give lower output on my dac?

Howerever, I also have done some mods on my d1 to replace most of all caps into audigrade parts,all diodes and opamp+tube rolling. Now I can hear that it's already much better than stock one that I heard.

One day upgrading my dac is the next project, I already have a recomended diy guy to get a NOS pure dac. So my complete plan will be like this :
Source (cdp/pc) -> DAC -> Preamp (tube/SS) -> Amp (SS)

By the fact that using low end preamp with opamp NE532 can improve the sound, I can make the conclusion that I still need a preamp, rite.

I'm still confused about this MVT preamp (or any vintage preamp) since there are not much readings that I get on earlier post. I bought aragon2004 without testing because of some good impressions in several post where it's still can be compared to modern amps.

note: vintage items for me maybe will not include sansui/marantz products due to their complexity inside of it.
 
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Ok let me explain it again.
A preamp, is something that takes a signal that is too low to drive the amplifier, and then boosts it to a level that can drive the amp to full power. It also has a volume control (attenuator) and various inputs switches.

A preamp is not needed in systems made in the last 20 years. Instead what is needed is an attenuator (volume control) and a buffer (zero gain amplifier). Since the source is loud enough all ready to drive the amp into clipping, you just need to turn the volume down to listen to it normally. Volume controls create a high impedance source so they cant drive amplifiers very well, and if its a long cable it will also roll of the highs. Think about trying to drive your speakers with a 1k resistor in the speaker cable.

From your complaints and what you have been trying, im guessing the stats on your dac are correct. I think your dac has a 5k out. This would explain why a preamp sounds better. Its easier to drive the preamp then the amp, and the preamp has an output buffer. But what ive been reading, the d1 has an output buffer, but why is it labeled 5k? You could experiment and try using the headphone out, thats guaranteed to have an opamp.

The only complaint seems to be the volume control being sub standard. So odds are you are using the d1 in bypass mode and using the volume control on the preamp.

My optimal layout for this rig would be this:
D1 in bypass mode
zero gain buffered attenuator (50k-100k input)
aragon2004

You are at least a little diy, and your buffered attenuator could just be a nice very low gain headphone amplifer (gain of 2-4).


For experiments, i would try replacing the volume control on the d1 with an ebay stepped attenuator of the same value, and try using the headphone out.
 
@nightanole

You gave so much inputs that i can implement, but I'll let my 'lampizator' do that for me :D
Is there any difference between stepped attenuator vs volume control ? Don't they have the same function ?

Just got the inner view of MVT,my first impression is that the allignment of the components a little bit messy and the component that are used maybe standard ones.

Should I buy this vintage preamp ?
 

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We build our own preamps here. It is true nightanole said you don't need boost on a CD player or computer to drive a power amp. You do on a magnetic phono cartridge for LP's. So I took a $15 disco mixer, changed it all around to delete the headphone amp output and DJ microphone input, removed the humming power supply from the steel box, changed the op amps for less hiss, changed the power supply to eliminate oscillations due to faster op amps, and eliminated interference from a CB radio driving by.
If you don't have LP's or magnetic tape head input, you don't need a preamp. You need an input source switcher and attenuator.
However, my disco mixer has the advantage, with the 10 kohm mixer resistors built in, I don't need to switch from one input to the other. I leave the pots where they are, and turn on the power switch to either the CD player, the FM radio (7 VAC out) or the magnetic phono cartridge.
You won't find this always on convenience in a preamp from Pioneer or Sony.
If you have other high level inputs like HDTV or computer, you may want to have more pots for your mixer. I converted the DJ mike input pot into a level setter for my FM radio input, which gets far stations with attractive programs, better in monaural.
Lots of people say the 5532 is a good sounding op amp. It doesn't have the fast slew rate requiring ceramic power supply de-coupling capacitors that the ST33078 op amps I used needed. But the 33078's sound great, very like my 12AX7 tube Dynaco PAS2 preamp: at 1/20 the watts consumed.
 
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