• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Jolida Glass FX III DAC tube recommendations

John Parkey

John Parkey

Member
Greetings. I have searched and did not see a tube recommendations thread for the Jolida Glass FX III DAC. I have that DAC with all of the factory upgrades. Have used Russian Electro Harmonax 12AX7EH tubes in place of stock tubes and that made a nice difference, richer sound, better dynamics, more detail. I just tried a pair of NOS RCA 12AX7 tubes and they are a slight improvement. More detail and wider range of volume, if that makes sense. Since I was using a Meridian 588 CD player as a transport, I also listened to the Meridian with its internal DAC. The Meridian DAC is the best of all, noticeably better than the RCA tubes.

So Please let me know if you have used any other tubes with the Jolida Glass FX III DAC which you really, really like. I own two of them and want to try something different. I get my tubes from Andie at Vintage Tube Services and am very pleased with his knowledge and service. He indicated the Muller tubes would be darker, which I do not want, and that the Amperex tubes would be slightly better but more expensive. He was not sure if I would be able to tell the difference.
 
Register to hide this ad
If you like your Meridian why spend money on tubes that shouldn't have been in a DAC in the first place? If you prefer the Meridian over the Jolida maybe try a modern DAC instead, there isn't a lack of inexpensive good performing DACs these days. Sorry, can't answer your actual question.
 
Hi gvl, nice to meet you here. I use a DAC when I stream music from the internet. The internal DAC in the Meridian CD player (or any other CD player that I know of) can not be used for this purpose. The Jolida glass FX III is what would be considered a modern DAC, and the RCA tubes have the same specification the stock tubes, just a different manufacturer. In fact, RCA invented the tube model in question, the 12AX7.
 
Tubes limit DAC performance, regardless of their specification. Some makers add tubes to DACs to appeal to the audiophile crowd, but in the end you get performance that is not even enough to clear the CD dynamic range. The fact you like the Meridian better is more or less a confirmation of this. I would just get an inexpensive DAC like Topping D50S or Schiit Modi 3 instead of going down the tube rabbit hole.
 
Last edited:
You need about 96dB of dynamic range and THD+N of about -90dB/0.003% to allow for truthful CD quality playback. Just for fun try to find a piece of tube gear with independently confirmed, or even claimed, performance matching those numbers. You may find a couple but those would be the exception. More typical is 60-80dB of dynamic range and comparable distortion levels. Jolida claims 126dB DR for the Jolida Glass FX III DAC, but it is impossible, best of best solid-state gear only get there. That's the DR of the DAC chip they are using, it has little to do with the actual device performance. The THD of 0.01% tells the real story. The Meridian CDP is spec'd at THD Less than -93dBFS.and noise Less than -93dBFS, those are believable numbers for a solid state CD player and its performance is sufficient to resolve full CD quality.
 
You can spend a lot of time and money rolling 12ax7s, but if it's fun and it sounds good, that's what it's all about. I enjoy listening to tubes despite their perceived, measured, or other deficiencies.
 
Thank you. I researched the popular input tube for the Schiit Valhalla 2 on Head Fi, bought a pair, and was astounded at the improvement. My first experience rolling tubes. So I thought I would try and save time and ask about tube rolling for my DAC here. Bought the RCA tubes based on Vintage Tube Services recommendation. Was surprised they did not make that much difference. Now I think the RCAs are good, they are a solid recommendation, it is that I am up against the inherent limits of the Jolida design/implementation. Has been interesting. But I do not intend to do much more. Despite the arguments to the contrary, the Jolida DAC sounds really good in a larger room with good equipment. Comparing with the Meridian is setting a high bar as the Meridian 508/24 and 588/24 may be in the top 10 ever made, or close.
 
Why not? I don't have any tubes inside any of my DACs, but curious to know why they're inappropriate?
 
A DAC's single purpose is to convert digital data to it's corresponding analog waveform with high precision and low noise to realize the ideal dynamic range that the digital data bit-depth allows for. A DAC with tubes introduces levels of harmonic distortions and thermal noise into the final signal which contradicts that simple purpose.
 
What quantities of distortion and noise are we talking about? Transformers introduce harmonic distortion, are they also ruled out because of that?
 
What problem does a transformer solve in a DAC that cannot be solved through other means and with lower distortion?
 
I'd like my earlier question responded to first before I go into the topic of transformers.
 
I saw that when it first came out. Back to my earlier question - how much distortion and noise are we talking about with a valve as output stage of a DAC?
 
xdd said:
I saw that when it first came out. Back to my earlier question - how much distortion and noise are we talking about with a valve as output stage of a DAC?
Click to expand...

One would hope to see 96dB free of distortion and noise for CD playback. Yes you can probably get away with less, but why? With careful design you can probably get that with tubes, but it rarely happens.
 
You must log in or register to reply here.
Back
Top Bottom