what preamp for hypex UcD180? DIY or used?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I've just built a hyped dual mono with 2 UcD modules, and I'm very satisfied with it. However, my nad preamp seems to be dying on me, but it doesn't seem to be on level with the UcD anyway (it's a "NAD monitor series stereo preamplifier 1000").

So I need a new preamp, but from what I've been able to read, a DIY preamp is a very ambitious undertaking, probably too much for me right now.

What I need in a preamp is a volume control, input selection (3 inputs will be fine) and headphone out. And of course, not limiting the sound quality too much.

So I'm considering 2 options:

1. Maybe there's a DIY kit somewhere I can get which includes a pre-made PCB, which fits my needs and is not too difficult to make. Does anyone know?

2. A good used preamp that's obtainable from Denmark (preferably buyable from somewhere in Europe).

I appreciate any help.
 
zhai said:
I've just built a hyped dual mono with 2 UcD modules, and I'm very satisfied with it. CUT
So I need a new preamp, but from what I've been able to read, a DIY preamp is a very ambitious undertaking, probably too much for me right now. CUT

So I'm considering 2 options:

1. Maybe there's a DIY kit somewhere I can get which includes a pre-made PCB, which fits my needs and is not too difficult to make. Does anyone know?

2. A good used preamp that's obtainable from Denmark (preferably buyable from somewhere in Europe).

I appreciate any help.

Dear Zhai,

as an absolute beginner, I have been considering the construction of an integrated stereo amp using Ucd 180 for a while without deciding to start because of the inability to design and build a proper preamp section to insert in the project (my earlier post is somewhere in the forum). In fact, I thought it would be probably pointless to build a separate diy preamp whenever you can insert a preamp section in the amp case (less connections). Searching for a commercial solution did not bring me any further since a preamp as good as Udc is still worth much more (also used) than I can afford.

Anyway, recently, I found this site:

http://www.diyclub.biz

in which I found some affordable preamp circuitry with remote control (I like this!!) but I am too ignorant to find out whether some of this gear would be good for a UcD preamp section and eventually how to design proper connections for a complete integrated amp.

So this might be an occasion for more knowledgeable people to enlighten us for further improvement...

Ciao
 
Preamp:
It depends on how much (or how little) you want to spend, single ended v/s balanced, passive v/s active ( "colored" or "neutral").

IMHO, the best price/performance would be some of the offers from twistedpearaudio.com , our mates ;)

For example, Kookaburra preamp/headphone amp (wich can be even balanced) plus Darwin source selector, or the new balanced preamp that they are develloping.

The kits are complete, very easy to build and what is most important, very transparent.
If you go that way you may consider puting Rubycon's ZL caps instead of the stock Pana FC caps, wich will deliver even better performance.

To put it in perspective, I have both a Kookaburra preamp (US$70 plus transformer and connectors) and a Transformed Based Volume Control (balanced) form Stevens&Billington's (around US$600) . Feeding UCD400 I found both equally transparent, maybe more punchy the Kookaburra but lacking some of the je ne sais quoi that the TVC brings; a softness and relaxed presentation that the (stock) Kookaburra lacked.

Hope this helps.
M
 
maxlorenz said:
Preamp:
It depends on how much (or how little) you want to spend, single ended v/s balanced, passive v/s active ( "colored" or "neutral").

IMHO, the best price/performance would be some of the offers from twistedpearaudio.com , our mates ;)

For example, Kookaburra preamp/headphone amp (wich can be even balanced) plus Darwin source selector, or the new balanced preamp that they are develloping.

The kits are complete, very easy to build and what is most important, very transparent.

CUT

Hope this helps.
M

Thank you very much maxlorenz the info is very useful and the site you suggested seems great.

It seems to me that a complete preamp would have to put together kookaburra+ lindberg+ darwin [+ volume control like joshua tree? but which one is suitable?] for a total of approx 150 usd + joshua (72-117 usd).
Now I have a couple of questions:

1) since I would really appreciate a remote control for volume and I am on a rather strict budget: I found this liteaudio remote motorised control w/ input selector for approx 30 usd (please be patient because download times from HK can be frustrating):

http://eshop.diyclub.biz/product_info.php?cPath=85&products_id=247

I was wondering whether I can eventually integrate this component with kookaburra in order to get a functioning decent preamp w/remote? How?

2) I have no building experience and therefore I am not confident with buildind kookaburra myself: do you think twisted pears can do it for me somehow?

Thanks very much again to every contribute

Z
 
Ciao Z,

Second question first:
These are really nice easy projects; good for starting DIY.
All twistedpear kits come VERY WELL packed and labeled. There's no instructions but the PCB is so clear that it is self-explanatory. Really, much fun.

First q:
Twistedpear's site has a support forum for question like these.
Kookaburra has a volume pot that is not on the signal path, to set the gain (or the attenuation) of the digital chip. I supose one can change the 100K pot from DIYclub for the 10K? from twisted's kit, but this remote control seems too much for your needs...I mean if you want both, Kookaburra and this kit.

Besides, look downwards at DIYclub, at the V-3310 single ended or balanced. Boy, that seems a great bargain to me!
Maybe that's all you need, plus you can get one (or more) of those nice 50VA R-core transformers to power it.
Mmmhh...
I'll study that Cristal chip to see if it is comparable to the PGA2311.

Ci vediamo...

M
 
maxlorenz said:
Ciao Z,

Besides, look downwards at DIYclub, at the V-3310 single ended or balanced. Boy, that seems a great bargain to me!
Maybe that's all you need, plus you can get one (or more) of those nice 50VA R-core transformers to power it.
Mmmhh...
I'll study that Cristal chip to see if it is comparable to the PGA2311.

Ci vediamo...

M

Thank you Max. I actually overlooked this device due to impossible use of this website but I have noting against using the v-3310 as a input and volume control device for the power amp that will be basically a Ucd 180 dual mono. I would only like to know if this combination works fine in terms iof impedance etc even without a proper preamp...

grazie 1000 e ciao
 
I bought both 3 volume kits from DIYclub.biz

The first went into a preamp based on Nukk's buffer, i didn't have a lot fo joy with that setup to be honest. The issue was the volume and input kit. I have to save the Nuuk buffer helped my Lm3886 no end. Since then i have built 2 more preamp based on the V03 and V3301 kits.

Both very good, i think the resistor ladder setup of the V03 worked very very well in my AD815 preamp. The V3301 is good too however is has a op-amp in it as well since it also can +db rating as well as minus.

Anyway the purer setup up of the V03 works best for me using a seperate Preamp setup. However class D stuff does have the same sorting of problems with input impedance that the LM based amps do IMHO.

Phil
 
Hey,

All diyclubs kits come with remote controlled volume and input selection

They come with no or very little documentation though none are that tough to get working. I may be able to help if you get issues.

Yes i am referring to the internal op amps in the Crystal chip, its still a very good volume control since it was used in the Conrad Johnson Coherence Preamp.

You can buy transformers for all of the kits via diyclubs but this does up the price of shipping a fair bit. Sourcing one locally may be a cheaper option.

On a word of caution with shipping the kits are a fair bit more expensive than they initially look. Get a quote before ordering!!!

Regards,

Phil
 
I understand from your kind msgs that in principle is possible to use both v-03 and v-3301 from diyclub.biz to insert them in the integrated amp that I would like to build based on dual mono ucd 180.

Assuming one of the above options is implemented do I have to insert a preamplifier also before going to the ucd input or can I live with only "passive" controls?

In case I would still need a preamplifier circuit which one you recommend? Since diyclub is good for me because it sells assembled modules, is there any of their preamp suitable for my use (shared post expenses)? A-15 would work well?

Thanks again

Z
 
yes you could use either, i personally would chose the v-3301. Try it as it and if needed add a gain stage later. On it own it makes a very high quality passive preamp. It is also worth buying all your input sockets from diyclub since they seem cheaper than any decent ones i have found in europe.

good luck,

phil
 
maxlorenz said:
Ciao Z,

....
Besides, look downwards at DIYclub, at the V-3310 single ended or balanced. Boy, that seems a great bargain to me!
Maybe that's all you need, plus you can get one (or more) of those nice 50VA R-core transformers to power it.
Mmmhh...
I'll study that Cristal chip to see if it is comparable to the PGA2311.

Ci vediamo...

M



I've used that board, although I purchased it locally, with a double mono UCD180AD. It is in fact very good. I would rate it as a good pot although I had no direct AB comparison. I've used an alps pot for testing prior to installing the board but there was some time in between.

The design is based upon/inspired by a Jeff Roland pre, if I'm not mistaken de concentra or concerta or alike. Although it is a somewhat older design it functions quite well.
 
indoubt said:


I've used that board, although I purchased it locally, with a double mono UCD180AD. It is in fact very good.

CUT

The design is based upon/inspired by a Jeff Roland pre, if I'm not mistaken de concentra or concerta or alike. Although it is a somewhat older design it functions quite well.

Thanks indoubt!

I would be very interested if you could share the details of your project (schematics, connections, photos, etc) in order to get started... Since I am a newbie I could never start without some practical help ;) from the people in this forum and up to now this has been very helpful...

Ciao
 
Been very far away a lot lately (Inner Mongolia)

UCD180.JPG


This is the only picture that I have, there are 2 boards of which you can see one.

The amp was for a friend and I don't have it nearby.
I think for a schematic you can better ask the supplier. A schematic is delivered when ordering.

A remote is included and works fine. The only thing is that it doessnt remember the channel when completely powered down.


Note that this photo was still in test phase and that the cabling has been cleaned up.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.