DIY Super Simple Preamp

[sachu888]

Hi Om,
I am going to order 2134 opamps.Fm Murli has compared both and 2134 was sounding better in ssp than 823.Hypnotoad also confirmed same at the last page of ssp thread.

Regards
Sachin

 

[doors666]

1 X B1 = 5 X SSP, approx. (if used AD823 which is costing more (~450 ea +shipping) due to Dollar escalations.)

I think you are talking from the whole cost perspective including psu, trafo, lsa etc. I was just talking about using a buffer preceding LSA. Either of these can be used, hence the question.

I remember seeing someone had used b1 with a wallwart adaptor, a pot and in a home made cab using plastic box too. There is a lot of scope on cost cutting there too if one is ok with a bit of a compromise.

 

[sachu888]

hi sachu,
pls let me know the opamp IC which will be provided as part of kit

opa2134 will be provided with kit.Pl let me know in advance if anyone wants different opamps

Regards
Sachin

 

[soundnovice]

opa2134 will be provided with kit.Pl let me know in advance if anyone wants different opamps

Regards
Sachin

is it possible to supply just the PCB without any components? this will give flexibility for everyone to try diff. components of diff.quality and price according to their taste. in that case what could be the price for the PCB?

 

[kroyin]

Can i get a AD823 ... i have few from the OPA group with me already (2134, 2111 )

 

[doors666]

If we are ordering from one of the big electronics stores, could we also get some good quality solder. usually its sold in bulk and becomes difficult for individuals to get it. how about some resin core 60/40 kester or something like that.

 

[sachu888]

is it possible to supply just the PCB without any components? this will give flexibility for everyone to try diff. components of diff.quality and price according to their taste. in that case what could be the price for the PCB?

Rs30O+shipping for one pcb.you can use components of your choice.btw i always use better quality components people participated in previous gb can confirm this.

Can i get a AD823 ... i have few from the OPA group with me already (2134, 2111 )

sure will do.

Can i get a AD823 ... i have few from the OPA group with me already (2134, 2111 )

no problem I'll provide.

How much would a b1 cost as compared to a ssp?

b1 would cost you 3 times more than ssp.I am talking about only b1 without any harware included.B1 pcb+matched jefets and two Axon caps alone cost twice than ssp.Pass Diy sells b1 pcb @ $40+$17(shipping).We managed to get everything(b1,ldr,powersupply with trafo)in rs 5500(approx). Members are free to use their own parts.This project is very simple and can be made on breadboard.

 

[murali_n]

Hi all,

Just got my new SSP board fitted in my cabinet and been running it for about an hour now. Initial impressions are that the sound is very detailed, bass improved over my stock board made from local components. Will post photos and write up once it is burnt in.

Thanks to sachin for making this possible.

N.Murali

 

[doors666]

b1 would cost you 3 times more than ssp.I am talking about only b1 without any harware included.B1 pcb+matched jefets and two Axon caps alone cost twice than ssp.Pass Diy sells b1 pcb @ $40+$17(shipping).We managed to get everything(b1,ldr,powersupply with trafo)in rs 5500.

Got it. I was just trying to figure out if a b1 standalone is not much more expensive than a ssp, we could go for that, but i guess thats not the case.

Ssp gb includes my small profit.It takes lot of time and effort,few fm advised me to start it as a second profession and I agreed. Members are free to use their own parts.This project is very simple and can be made on breadboard.

That means we are going to see more group buys in future. When are we opening for requests

 

[iaudio]

100K is not deciding gain but that is to shunt output to ground and stop unwanted oscillation at output (this may be safely ignored or value could be increased). Gain is decided by 8.2K and 10K. I am using 10K in place of 8.2K.


1 X B1 = 5 X SSP, approx. (if used AD823 which is costing more (~450 ea +shipping) due to Dollar escalations.)

It has too much gain, I am going to change out the 100k resistor in the feedback loop to a lower value which should take care of that.

Omishra, I kinda got confused by this post by hypnotoad.

 

[omishra]

Omishra, I kinda got confused by this post by hypnotoad.

I think you read the early posts in that thread. In the final version feedback values gone for change. Please read the complete thread and let me know. I may need correction or same with you also. "give and take, here and there."

 

[kroyin]

Om what is the gain with 8.2 & 10k....sorry too lazy to read the referred post

 

[iaudio]

omishra, I am in the process of going thru it.
Will get back to you if I find anything. But I am sure you know better.

 

[omishra]

Om what is the gain with 8.2 & 10k....sorry too lazy to read the referred post

It is non inverting amp with gain 1+(10/8.2) = 2.1X. After using 10K in place of 8K it is 2.

 

[murali_n]

Hi all,

Some Photos of my SSP Preamp & CNC Phono:

Front, Back, Internal & Isometric views :

 

[doors666]

for small diy projects like this, odac, o2 etc, what is the most suitable material for a small time home made enclosure.

1. plastic
2. aluminium/hindolium etc
3. stainless steel (can this be drilled/filed easily?)
4. tin
5. wood

which is the best among the metals. if not using metal, then which one, do emi/rf etc impact performance. can some kind of shielding be used like aluminium foil glued to the plastic/wood surface.

what about the trafo/wallwart etc. is it better to have it internal or external. extra weight will add some stability to light enclosures, specially if using rca cables. of course heavy feet can always be used.

O2 uses 15vac supply. is a trafo or wallwart the same thing in this case. the wallwart wont have any other circuit other than the trafo right?

 

[GeorgeO]

You can also consider a ready made enclosure from SP Road.

 

[doors666]

You can also consider a ready made enclosure from SP Road.

any idea which shop is selling these, how's the quality or price. do they customize it also with faceplate. are there various sizes available.

 

[omishra]

for small diy projects like this, odac, o2 etc, what is the most suitable material for a small time home made enclosure.

...

which is the best among the metals. if not using metal, then which one, do emi/rf etc impact performance. can some kind of shielding be used like aluminium foil glued to the plastic/wood surface.

what about the trafo/wallwart etc. is it better to have it internal or external. extra weight will add some stability to light enclosures, specially if using rca cables. of course heavy feet can always be used.

O2 uses 15vac supply. is a trafo or wallwart the same thing in this case. the wallwart wont have any other circuit other than the trafo right?

Any cabinet provides shielding is good like metal, wooden laced with kitchen foil etc. I personally prefer ready made which are available ~100Rs and serves better, look better. My favourite are 6"(W) X4"(D)X 2"(H) which you see any many of my preamps.

Consider what output wall wart has, AC or DC. If you get AC wall wart then you can put PS rectifier and regulator inside the same box. This makes mains AC away from preamp and its welcome. DC wallwart won't be useful as these OPamp needs dual rail and for driving from single rail PS some modifications are needed like virtual(pseudo) ground.

For others consider this "SSP ->Volume control->SSP" as excellent preamp for impedance matching buffers which won't loose any music while controlling level. My personal opinion goes for AD823 which does no coloration, just transparent and invisible in the audio path.

 

[doors666]

Any cabinet provides shielding is good like metal, wooden laced with kitchen foil etc. I personally prefer ready made which are available ~100Rs and serves better, look better. My favourite are 6"(W) X4"(D)X 2"(H) which you see any many of my preamps.

Thanks, will check it out.

Consider what output wall wart has, AC or DC. If you get AC wall wart then you can put PS rectifier and regulator inside the same box. This makes mains AC away from preamp and its welcome. DC wallwart won't be useful as these OPamp needs dual rail and for driving from single rail PS some modifications are needed like virtual(pseudo) ground.

I was asking this for O2, which requires about 15V AC power. If I get a 15VAC adaptor, inside it will just have a trafo right. no other circuit in the AC adaptor unlike in DC adaptor which requires rectifier, capacitors etc.