I have finally gotten round to rebuilding the Daniel preamp in a dual mono configuration.All voltages are within a couple of voltages of those listed by Joe Curcio in the original article and appear stable. I have used the dual 340 transistors in the ht supply. The 20k anode load resistors in the second and final stages are running extremely hot;close to 100 degrees;can't remember if this was the case when I did the original build.The resistors are 5 watt Mills.Is there anything I need to check.Any advice gratefully received.TIA
Hi, Going srictly from memory, and it was a looooong time ago!
If i remember correctly, the HT supply from the 317 pre reg was around 265V, and the outputs from the individual op amp/transister followers was 250V.
Also i think the parallel ECC88 sections in the second and third stages were run with around 60 to 70V at the Anodes.
I used a a pair of 39K 2Watt Holcos as Anode load resistors, they got hot, but i never had to change them.
Can you check you have the correct value cathode resistors? What voltage is on the Anodes?
Sorry cant be more help.
Cheers.
If i remember correctly, the HT supply from the 317 pre reg was around 265V, and the outputs from the individual op amp/transister followers was 250V.
Also i think the parallel ECC88 sections in the second and third stages were run with around 60 to 70V at the Anodes.
I used a a pair of 39K 2Watt Holcos as Anode load resistors, they got hot, but i never had to change them.
Can you check you have the correct value cathode resistors? What voltage is on the Anodes?
Sorry cant be more help.
Cheers.
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I beg to differ. If you wish a preamplifier that has virtually no sonic signatures, not harsh, not sterile, listening tested under strict conditions, then the proper E88cc is the tube to use.
I am not saying the Daniels is the best, it certainly is not imo. But the design makes all the difference in the world.
Cheers.
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Thanks for the reply.As you say the voltage after the 20k resistor is in my case 68/70 volts so would appear to be ok.I was just concerned at the temp.For a 5 watt resistor the Mills are on the small side.Looks like things are ok;I will hook it up tomorrow with an old amp and speakers and try it out.
I connected the Daniel up with a chipamp and a pair of old 4" drivers this morning.CD works/sounds ok but switching to phono results in hum which gets louder as the volume control is turned up.When the music starts you can't hear the hum and it does'nt sound to bad all things considered.I have used unshielded twisted pair wiring and the amp is uncased.Any advise as to what to check will be much appreciated.
Cathode resistors are as listed in the original article 390R and apart from using 5 watts for the 20k's all others are as listed.
Is the hum/buzz when using the phono input and which gets louder when the volume control is turned up due to a ground loop or would a ground loop be a constant level no matter what volume setting.I have never experienced this before so am unsure of what to check for.
Is the hum/buzz when using the phono input and which gets louder when the volume control is turned up due to a ground loop or would a ground loop be a constant level no matter what volume setting.I have never experienced this before so am unsure of what to check for.
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Hi,
I had mine in high gain mode with 100R on the cathode of the input cascode, and i found it very quiet and well behaved, with the right valves.
I added a mosfet follower to the line stage as i needed to drive longish cables.
I found it quiet enough for use with high output moving coils, and ran it for many years without issues or repairs.
I tried a few other published valve preamps around that time, but always came back to the Daniel.
But ultimatly i abandoned using a valve for the front end, and went over to a fet, like many others!
Though i hear a 6c45p can be used for mc duty, i have purchsed a small stash of these and intend to give it a try someday when time allows.
Meanwhile i am using this:http://www.diyaudio.com/forums/tubes-valves/170012-fet-6gk5-ecc88-mc-phono-stage.html
Enjoy your Daniel.
Cheers
I had mine in high gain mode with 100R on the cathode of the input cascode, and i found it very quiet and well behaved, with the right valves.
I added a mosfet follower to the line stage as i needed to drive longish cables.
I found it quiet enough for use with high output moving coils, and ran it for many years without issues or repairs.
I tried a few other published valve preamps around that time, but always came back to the Daniel.
But ultimatly i abandoned using a valve for the front end, and went over to a fet, like many others!
Though i hear a 6c45p can be used for mc duty, i have purchsed a small stash of these and intend to give it a try someday when time allows.
Meanwhile i am using this:http://www.diyaudio.com/forums/tubes-valves/170012-fet-6gk5-ecc88-mc-phono-stage.html
Enjoy your Daniel.
Cheers
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Thanks;I've been listening to some cd's this morning and am pleased with the Daniels performance.On phono I need to revert back to high gain as I am having to go nearly to full volume to get decent output.I think I'm going to have to make a deeper case having gone dual mono and therefore slightly bigger pcb's.
Your current phono stage looks interesting although I don't know whether I would have the confidence to tackle point to point.Is it a marked improvement over the Daniel's phono stage?
I'm currently using a Pass Labs Xono clone which uses Jfets in the mc stage and sounds pretty good.
Your current phono stage looks interesting although I don't know whether I would have the confidence to tackle point to point.Is it a marked improvement over the Daniel's phono stage?
I'm currently using a Pass Labs Xono clone which uses Jfets in the mc stage and sounds pretty good.
Hi,
Certainly from a noise point of veiw, at least with low output mcs, its a large improvement over the Daniel, it also has much lower output impedance, so interconnect cable length and the resulting bandwidth loss is not an issue either.
My circuit could probably be improved with the addition of the Salas shunt reg, but i wanted to keep it simple, avoiding large heatsinks etc.
As it stands with the VR tube regs, i would say detail retrieval, noise, and percieved bandwidth, or slam factor are much better than the Daniel, and the available gain is much higher. It sounds big, and lifelike, with a broad deep soundstage
But of course i am biased, and i also have no aversion to some solid state designs, so the use of a input fet dosent bother me as long as it delivers the goods.
As far as point to point wireing goes, i find it just makes things much simpler if modifications or changes are needed to the initial paper design. And its quicker to get the thing up and running.
Cheers.
Certainly from a noise point of veiw, at least with low output mcs, its a large improvement over the Daniel, it also has much lower output impedance, so interconnect cable length and the resulting bandwidth loss is not an issue either.
My circuit could probably be improved with the addition of the Salas shunt reg, but i wanted to keep it simple, avoiding large heatsinks etc.
As it stands with the VR tube regs, i would say detail retrieval, noise, and percieved bandwidth, or slam factor are much better than the Daniel, and the available gain is much higher. It sounds big, and lifelike, with a broad deep soundstage
But of course i am biased, and i also have no aversion to some solid state designs, so the use of a input fet dosent bother me as long as it delivers the goods.
As far as point to point wireing goes, i find it just makes things much simpler if modifications or changes are needed to the initial paper design. And its quicker to get the thing up and running.
Cheers.
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What is up Guys,
Why are we picking on poor Daniel. Daniel's dad Joe Curcio was a leader. Fashions and preferences change.
I learned a lot from Daniel, including; voltage doublers, Master and Slave (made from a op-amp) voltage regulators, that power supplies do color the sound and zero crossing triacs. Someone tell the why and how of a zero crossing triac?
If you can design a better circuit have at it.
DT
Why are we picking on poor Daniel. Daniel's dad Joe Curcio was a leader. Fashions and preferences change.
I learned a lot from Daniel, including; voltage doublers, Master and Slave (made from a op-amp) voltage regulators, that power supplies do color the sound and zero crossing triacs. Someone tell the why and how of a zero crossing triac?
If you can design a better circuit have at it.
DT
I hope my posts did'nt appear to be knocking Joe Curcio's Daniel as I have only just rehashed it as a completely dual mono unit with completely seperate H/T and heater supplies. Once I have it recased I will be giving it some extensive listening. Now being retired I guess I'm always looking for another project to enhance my listening pleasure.
Hi DT retirement is pretty good thanks.I'm able to get out for bike rides on my American built Lynskey and listen to music and build some fine sounding amps [thanks diyaudio ] whilst pretending to be a house husband and being kept in the manner I'd like to become accustomed too by my good lady.
Curcio Daniel Preamp
Dear Alex,I would very grateful if you can give me a copy of the Daniel Preamp
I have a pcb but no paper work,I will pay you for your trouble. Thx await a email from you. email; peter.gay@gmail.com
Dear Alex,I would very grateful if you can give me a copy of the Daniel Preamp
I have a pcb but no paper work,I will pay you for your trouble. Thx await a email from you. email; peter.gay@gmail.com
Curcio Daniel Preamp
Dear Member. If you find the paper work I will buy a copy from you.I got a pcb Curcio Daniel Preamp but no paper work to finish it off, Thx await a email from you.Thx. Peter
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