Quick Product Poll! Tube Buffer with Volume Control?

paul79 · « **Reply #40 on:** 8 Jan 2019, 02:16 am »

And you need to make it! I strategically posted here.....

Rusty Jefferson · « **Reply #41 on:** 8 Jan 2019, 05:28 am »

Looks like I'm in the minority about a volume control. My dac(s) don't have them and I wouldn't want to have to get a dac with volume control in the future. Perhaps a switch that could defeat volume for those who don't need/want it?

Unity gain is fine with me. Single ended, 1 in 2 out. Quiet enough to use with 100db + speakers and low output impedance, as mentioned. Protection from passing dc also. All that's worth $2k-ish to me. Doesn't need to come with tubes installed.

paul79 · « **Reply #42 on:** 8 Jan 2019, 05:38 am »

Quote from: Rusty Jefferson on 8 Jan 2019, 05:28 am

Looks like I'm in the minority about a volume control. My dac(s) don't have them and I wouldn't want to have to get a dac with volume control in the future. Perhaps a switch that could defeat volume for those who don't need/want it?

Unity gain is fine with me. Single ended, 1 in 2 out. Quiet enough to use with 100db + speakers and low output impedance, as mentioned. Protection from passing dc also. All that's worth $2k-ish to me. Doesn't need to come with tubes installed.

There are several nice line stages out there with a volume control at or maybe a bit more than your budget. Dan makes some really great ones.

Dan. the volume control in my DAC is FPGA based and runs at 64bit at max volume. So allot of bits to throw away with attenuation, and never cause a sonic issue.

Rusty Jefferson · « **Reply #43 on:** 8 Jan 2019, 01:32 pm »

Quote from: paul79 on 8 Jan 2019, 05:38 am

There are several nice line stages out there with a volume control at or maybe a bit more than your budget. Dan makes some really great ones....

Could you show me some, please?

Again, need almost zero output impedance to biamp with solid state amplifiers, 6db or less gain, dead quiet for use with 100db+ speakers, tube output stage, volume, protection from dc (the only issue with the Microzotl). See reply #7.

The only difference you and I are looking for is volume control so I don't have to buy dacs with volume. Don't need multiple inputs, tape, invert, xlr, etc. Wouldn't vinyl only people also be interested in this buffer if it had volume?

paul79 · « **Reply #44 on:** 8 Jan 2019, 04:36 pm »

I am sure I could find something. I would do my homework. I would seek out companies that let me trial the products in my system to make sure they are what I am looking for. I cannot make any recommendations other than if I was looking to add features, such as vinyl, multiple sources, volume control, I would look for more of a full featured line stage.

I also, even in a bi-amp scenario, do not see why you would need almost zero output impedance? Depends on the destination components to a degree, and the load they present, sure. There are plenty of nice quiet tube preamps out there that have plenty low enough output impedance. Which is what the buffer would then turn into if you added all these features.

Maybe Dan can add all these things for you, I don't know, but I fail to see why some of your needs are actually important for your system. You might not find exactly the gain spec or the output impedance you are looking for, but within reason, you can get close.

modwright · « **Reply #45 on:** 8 Jan 2019, 04:37 pm »

I am listening to all of you! Adding a defeatable VC is not a problem, just a high quality toggle. It is true that not every DAC has a VC.

I may start with a simple product offering as proof of concept with just RCA in-out and no VC. Based on field testing and feedback, we could roll out models with a larger feature set.

Thanks,

Dan

paul79 · « **Reply #46 on:** 8 Jan 2019, 04:42 pm »

I hope you do Dan!

Thanks for letting me rant here. I enjoy these discussions. See there Rusty? Looks like you are in the right place.

modwright · « **Reply #47 on:** 8 Jan 2019, 05:06 pm »

All good! It is market research for me and who better than people who would be interested in our gear!

Dan

RDavidson · « **Reply #48 on:** 8 Jan 2019, 09:06 pm »

Any thoughts on tube type? I really like 6SN7's. Even the low cost examples of this tube sound pretty decent and there's a wide variety of flavors to roll. I think their reputation for being too "tubey" and/or too microphonic is anecdotal. As always, a lot depends on the circuit design. Sure, their big glass is more microphonic than a small tube. There are dampers out there that help with this. In my opinion, 6SN7's do more right than wrong especially where tone and naturalness is concerned.

modwright · « **Reply #49 on:** 8 Jan 2019, 09:17 pm »

My choice honestly will be 6922/d6j8/7308 family. This is because I like the tube, they are plentiful and in current production and their low plate impedance and high transconductance make them ideal for our circuit.

paul79 · « **Reply #50 on:** 8 Jan 2019, 09:57 pm »

Sonically excellent choice using the 6DJ8. No question. How are the new production ones of these holding up though Dan?

Mark V. · « **Reply #51 on:** 8 Jan 2019, 10:12 pm »

I could be interested, but volume control makes it much more versatile in my opinion. (and for me the only useful option) At least 2 switchable inputs would also be nice.

Thanks,

Mark

Rusty Jefferson · « **Reply #52 on:** 8 Jan 2019, 10:13 pm »

Quote from: modwright on 8 Jan 2019, 04:37 pm

I am listening to all of you! Adding a defeatable VC is not a problem, just a high quality toggle. It is true that not every DAC has a VC......

Thank you for the consideration. Perhaps it could just be optional?

Paul79, I'm not sure why you think I'm looking for a full featured preamp. I'm after the same thing as you.......with volume control.

If you can find something that performs as well as the Microzotl and has protection from passing DC for that price point let me know. It's an amazing piece of gear. LTA just recently released a version as a full featured preamp with protection, but at more than twice the price. Can't afford it and don't need all the features.

modwright · « **Reply #53 on:** 9 Jan 2019, 12:41 am »

What level of protection does the microzotl provide or not provide? Does the protection actually include DC sensing and shutoff?

Rusty Jefferson · « **Reply #54 on:** 9 Jan 2019, 01:17 am »

Quote from: modwright on 9 Jan 2019, 12:41 am

What level of protection does the microzotl provide or not provide? Does the protection actually include DC sensing and shutoff?

The "basic" Microzotl (not the new MZ preamp) is a headphone amp that had rca outputs added so as to use it as a preamp. It's direct coupled, and if used with a direct coupled amplifier(s) and say you turn on the amplifier, then the MZ, or if they are both on and your power goes off/on it passes a large shot of DC when it turns on/back on. Dave Berning warned me about this, but when I was demoing it and had a brief power failure I honestly don't know how my speakers survived the surge. I immediately removed it.

My understanding is the new MZ dedicated preamp is the same circuit, but with a suppression circuit to prevent passing DC.

Rusty Jefferson · « **Reply #55 on:** 9 Jan 2019, 01:35 am »

I should also mention it (like all the Berning ZOTL designs) is one of the most transparent, best sounding pieces of audio gear I've tried. I'm sure the new dedicated preamp is superb, but it's pricey and too full featured for my needs.

RDavidson · « **Reply #56 on:** 9 Jan 2019, 01:38 am »

Quote from: modwright on 8 Jan 2019, 09:17 pm

My choice honestly will be 6922/d6j8/7308 family. This is because I like the tube, they are plentiful and in current production and their low plate impedance and high transconductance make them ideal for our circuit.

Cool. I've had good experiences with 6DJ8's too.

I totally understand people's desire for volume control and other features, but the more features that are added, the further away it gets from a simple in/out interface....and it becomes a unity gain line stage. Maybe 2 "mini" components makes more sense than just one? 1. tube buffer. 2. Unity gain line stage.

modwright · « **Reply #57 on:** 9 Jan 2019, 01:40 am »

OK, I see. The buffer is cap coupled in and out and there is a mute circuit that defaults to mute when powered off.

paul79 · « **Reply #58 on:** 9 Jan 2019, 02:01 am »

Quote from: RDavidson on 9 Jan 2019, 01:38 am

Cool. I've had good experiences with 6DJ8's too.

I totally understand people's desire for volume control and other features, but the more features that are added, the further away it gets from a simple in/out interface....and it becomes a unity gain line stage. Maybe 2 "mini" components makes more sense than just one? 1. tube buffer. 2. Unity gain line stage.

paul79 likes this

modwright · « **Reply #59 on:** 13 Jan 2019, 10:09 pm »

Concept/proto of the Analog Bridge Tube follower. I am thinking $750 retail with one pair of RCA inputs and two pairs of RCA outs. No VC or balanced outs for this design. As shown includes a 5V DC, 2A linearsupply. Not sure if this would be part of the standard design.

Enclosure will be sexy and slim with MWI style. Designed to fit easily into the system with a compact footprint.

Next step concept drawings and enclosure design. Let me know if you want to be added to the wait list. This just means that we will contact you when it is available.