Your DAC looks really lovely Debra! A true work of art.
I'm curious about your tube amp - in the picture for Tube Depot the usual output transformers look like the style of normal mains trafos, i.e. EI cored. Are the Lundahl trafos you mentioned the same kind of construction?
I'm curious about your tube amp - in the picture for Tube Depot the usual output transformers look like the style of normal mains trafos, i.e. EI cored. Are the Lundahl trafos you mentioned the same kind of construction?
Thanks!
The Lundahl transformers are C core transformers. They were an upgrade from the standard transformers that usually come with the kit.
The Lundahl transformers are C core transformers. They were an upgrade from the standard transformers that usually come with the kit.
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Interesting build Debra!
How do you switch betwenn inputs (eg from USB to SPDIF)?
I see 2 different input cards and presume output is from the second card in I2S format, but wonder how you switch inputs...
Many thanks!
Claude
How do you switch betwenn inputs (eg from USB to SPDIF)?
I see 2 different input cards and presume output is from the second card in I2S format, but wonder how you switch inputs...
Many thanks!
Claude
Seen that, hence the question... care to elaborate how it works?
I mean is the switch to switch between cards (say USB and what is not), so a choice of 2?
Then on the non USB card (SPDIFs) what signal gets priority?
Or did you find a way with a push button to go through the various inouts, but then how?
Sorry, newbee on all this
No problem if a hassle Debra, just asking...
Claude
I mean is the switch to switch between cards (say USB and what is not), so a choice of 2?
Then on the non USB card (SPDIFs) what signal gets priority?
Or did you find a way with a push button to go through the various inouts, but then how?
Sorry, newbee on all this
No problem if a hassle Debra, just asking...
Claude
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Claude
The SPDIF board has inputs for a switch. It is a momentary contact switch that will cycle through the inputs.
Don't know about the Bluetooth
The SPDIF board has inputs for a switch. It is a momentary contact switch that will cycle through the inputs.
Don't know about the Bluetooth
Thanks Debra!
It will cycle through the inputs... is there a provision for an additional input on tio of USB and fiberglass and coax you fitted?
Many thanks again
Claude
It will cycle through the inputs... is there a provision for an additional input on tio of USB and fiberglass and coax you fitted?
Many thanks again
Claude
Claude - the input card I normally recommend has two coax S/PDIF inputs, a Toslink and an external I2S (which usually receives the USB input I2S). So you could handle Bluetooth if you used a BT-> Coax board. Something like this : https://www.aliexpress.com/item/1005001771461083.html
Excellent news, very good to know!
The only thing I need to find out is if I also need provision for a volume control, but that's a very specific question for my secondary system linked to apps my wife uses... not easy knowdays with DIY to have a DAC that includes all the usual features, but thanks to you it is made pissible at least. The DAC in my own main system doesn't even do volume control, USB and phase inversion, but wife and kids want it simple from a phone in the living room.
Many thanks for all that... again!
Claude
The only thing I need to find out is if I also need provision for a volume control, but that's a very specific question for my secondary system linked to apps my wife uses... not easy knowdays with DIY to have a DAC that includes all the usual features, but thanks to you it is made pissible at least. The DAC in my own main system doesn't even do volume control, USB and phase inversion, but wife and kids want it simple from a phone in the living room.
Many thanks for all that... again!
Claude
A potential customer has asked me if Celibidache can drive headphones directly. The answer is 'no' for the stock version. However if you have high impedance HPs (I have Drop HD6XX which are 300ohm) you can fairly easily modify (two resistors to change or over-solder) your Celibidache to drive them to comfortably loud levels. If you have 600ohm HPs (Beyerdynamic DT880s for instance) they can also be driven but without a gain increase (two more resistors to change) they won't go loud. In addition to the resistor changes you also need to increase the value of the output coupling caps (I use 1000uF/16V).
Claude - as you were talking volume controls, do you have any interest in an autoformer volume control? I am thinking one up as it seems the lowest value of pot easily available is 5kohm and that amount of resistance adds noise. With an autoformer volume control the impedance can be (at the very least) an order of magnitude lower, giving a worthwhile noise improvement. It won't be as convenient as a pot though because it will have steps and need some digital circuitry to control it. But for the ultimate SQ I think autoformers are hard to beat.
Hi again,
Autotransformers have indeed that impedance virtue. Usualy they are quite expensive and while they may allow VG sound quality if done properly, they don't allow easily a remote volume control.
At that stage the DAC I mentioned would be for a secondary system with lazy people not wanting to have many "things to press or launch", while though not seeking the absolute sound quality. So non expensive and easy going... not really autotransformers.
Me with my main system, that's different: I seek for the best possible DAC (Celibidache?) but don't need a remote control for volume... and have already all what I need regarding preamp and volume adjustability 🙂
But thanks again for thinking about it!
Claude
Autotransformers have indeed that impedance virtue. Usualy they are quite expensive and while they may allow VG sound quality if done properly, they don't allow easily a remote volume control.
At that stage the DAC I mentioned would be for a secondary system with lazy people not wanting to have many "things to press or launch", while though not seeking the absolute sound quality. So non expensive and easy going... not really autotransformers.
Me with my main system, that's different: I seek for the best possible DAC (Celibidache?) but don't need a remote control for volume... and have already all what I need regarding preamp and volume adjustability 🙂
But thanks again for thinking about it!
Claude
I agree they are usually rather expensive, but I have an idea to make a much cheaper one. For a start using ferrite cored transformers rather than the more usual permalloy. Given they need some kind of digital control, a remote control comes more naturally to an autoformer VC than for a standard pot which needs to have a motor added. A digitally controlled autoformer just needs an IR receiver tacked on to its CPU (plus software of course).
Thanks for the feedback.
Thanks for the feedback.
Then it all depends on price point really... indeed worth considering then.
As a baseline, a continuous adjustable acceptable pot (not the very best but enough for most), namely a complete kit (with remote) around a genuine motorised Alps RK27, costed slightly more than 36E (1y back).
Further, quite a few steps would be required to adjust the volume, but then if it can be a competitor to the above an autotransformer is worthwhile looking into. It has indeed that impedance advantage and other caracteristics that could enhence your DACs sound further...
Keep us posted
Claude
As a baseline, a continuous adjustable acceptable pot (not the very best but enough for most), namely a complete kit (with remote) around a genuine motorised Alps RK27, costed slightly more than 36E (1y back).
Further, quite a few steps would be required to adjust the volume, but then if it can be a competitor to the above an autotransformer is worthwhile looking into. It has indeed that impedance advantage and other caracteristics that could enhence your DACs sound further...
Keep us posted
Claude