Quick Product Poll! Tube Buffer with Volume Control?

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RDavidson

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #180 on: 27 Apr 2021, 04:07 am »
Not really sure what the point of your post is jjss49, especially posting eBay advertisements. There are indeed many crappy, low quality, tube buffers out there that can be bought for a few hundred bucks. Lots of choices from China. If that's your cup-o-tea have at it. They won't be as well built nor perform as well as Modwright.

jjss49

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #181 on: 27 Apr 2021, 05:19 am »
rdavidson, why are you so offended and what do you know about what is my cup of tea?

my point is on the first line of my post - what is old is new again -- if what dan proposes is a tube buffer with no volume control, one set of rca inputs one set of rca outputs

the musical fidelity buffers were good in their day, they were not crap, just as musical fidelity is not crap today, conceived and brought to market by antony michaelson in the uk (some of this mf 'crap' has even been stereophile class 'A' gear) :) ... they enhanced many a system that needed the same help that dan's proposed unit will bring, solving the same problem...  a leaned-out sound from digital sources due to a lack of a good, properly impedance matched output stage, plus sonic beautification from small signal tubes

the MF X10 v3 in 2004 was MSRP $400, makes it just short of $800 in 2021 dollars

i am a fan of dan's... have owned 5 of his preamps/amps and modded cdp's over the years, still have 2 of them, both bought direct... i am just suggesting he try to do something more distinctive if he is going to work on a new product, as busy as he is

he is here seeking honest input in this public forum, and this is mine, from an actual paying customer
« Last Edit: 27 Apr 2021, 02:12 pm by jjss49 »

RonP

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #182 on: 27 Apr 2021, 01:01 pm »
The initial product will be as follows:
RCA in and RCA out.
< $995.
No volume control, no remote.
Compact enclosure with exposed tubes.
dWright instruments Inc.[/size]

Balanced in/out option available?

Rusty Jefferson

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #183 on: 27 Apr 2021, 04:17 pm »
What do you guys think of the following, in lieu of a full tube mod to a digital source?

Tube Buffer with volume control, ideally remote control.
Two inputs: Simple system with say vinyl and digital source.
Zero gain, low output imepdance for matching with any SS or tube amp.
Low Noise, Low distortion.

Goal: Act as a preamp/passive preamp or volume control while adding BUFFERING, which is the most important part of any preamp!
Mulitple source input and R/C volume act as preamp functions, but without unwanted complexity, circuitry and cost.

This would add tube tone to any system, SS or otherwise.
It would improve the sound of less than stellar digital sources.
Can be used with different digital sources.
Also, being as how it is unity gain, would also integrate into a HT system without the need for a bypass.

Form factor would be medium size, one box.
Finish would be classic ModWright: Elegant, clean and sophisticated.

Cost: $995 as a starting point.

Input welcome!

Thanks,

Dan

This would be what I'm seeking. Volume, even without remote needed. I could live with 1 input and no selector switch. As long as the output impedance was low, I could use a "Y" jack on the output.

Russ L

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #184 on: 27 Apr 2021, 05:23 pm »
OK guys, it is time to resume this thread and bring this product to the finish line!

First of all, it has been a strange year plus, for all of us! For me personally, I got off track, and I feel now like I am back! Like many of you, a lot of introspection, time alone and such a change in lifestyle. I don't really feel like the same person that I was before 2020. Not all for the bad, many ways for the better. But, all the same, I kind of got knocked off course.

I have been focusing on the KWH 225i Hybrid integrated amp and the PH 9.0 tube phono and PH 9.0X upgraded version. These products are doing well and I am now feeling inspired to take (code name: 'The Buffer') to market. Product name is much cooler, but that will come later!

While I have asked what everyone wants, and weighed it all, I have decided to do the following:

The initial product will be as follows:
RCA in and RCA out.
< $995.
No volume control, no remote.
Compact enclosure with exposed tubes.
Likely tube rectified.
High bandwidth, low distortion, low noise and very low output impedance to match with ANY amp, tube or SS!
Lastly, I have an idea for tube rolling and flexibility of tone and preference, that I believe will be well received!


The whole intent of this design was to take the 'mod' out of the the digital source and make this a product that can be used in any system with any analog signal device. I.e. between DAC and amp, DAC and preamp, any other source analog signal path in, out to amp/preamp. Many of you have SS systems and want to add tubes, but don't want the hassle of biasing a tube amp or are uncertain about going to a tube preamp. Many of you also have digital sources with built in volume control that drive amps directly. This product can add 'the tube sound' to your system, without adding noise, and will also offer your amp the VERY low output impedance that it wants, to perform its best! No passive volume control and offer the impedance matching of an active circuit such as an active preamp or buffer.

Next step is to get the rubber on the road and design the enclosure and finalize the circuit.

I will share progress and images of the project here and I hope that you will share your frank feedback.

This project began some time ago and I know many of you thought it had died on the vine, but rather, it has simply matured...

I am ready for an exciting new product that is affordable, flexible and will fit ANY system!

Thank you all for your support, feedback and patience!

Dan Wright
CEO, ModWright instruments Inc.


Hi Dan - been watching this thread for a while but in the interim, two weeks ago, I sprung for an Oppo 205 ($2,750  :roll:)  I spoke to Kristen about adding an analog input to the 205 as part of your 205 mod.  She explained, in great detail why that could not be done (hope you're paying her the big bucks, IMHO she deserves it).  Since it can't be done, and I've already paid through the roof for my 205 (but very happy) the "Buffer" would be an economical substitute for the full 205 mod.

But I'm back to the same issue, I need an analog input for my TT.  I don't need a volume control as the 205 has a very well thought out digital volume control. And I don't want to purchase a preamp; the whole point of the 205 driving my monoblocks directly.  So I like what you're proposing, just need two inputs (and I guess a volume control for the TT input).

Thanks for all your great work, Kristen too.  :D

Russ on Long Island

AndrewA

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #185 on: 27 Apr 2021, 09:27 pm »
I completely understand your desire to start simple and go from there, but let me just say that was caught my attention was a tube buffer with remote-controlled volume control and RCA and XLR in and out, i.e. the full Monty.  Perhaps it could be modular, with those offered as add-on options.

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #186 on: 27 Apr 2021, 09:58 pm »
Hi guys, the intent is to make the product modular. The initial offering will be RCA in and out only.
Balanced inputs and outputs would be expensive as the ideal way to do this would be with transformer coupling. It can be done as an add cost offering.
RE R/C VC, that too could be done, but my intent was to offer a product to integrate into a system that already contained a VC as most digital sources do these days. It would pretty much be a unity gain preamp as described. Having said that, with the modular approach, this could be done too.

Yes, the 205 only offers a tube analog OUTPUT stage, but this tube buffer could work with ANY source!

I think you will like my idea when you see the final design. It will allow for A LOT of flexibility in terms of tailoring the sound! I will also make the fuse(s) easily accessible via external port for those who like to upgrade their fuses.

Thanks! More soon!

Dan

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #187 on: 27 Apr 2021, 10:27 pm »
OK, I can see the desire for a VC. I am trying to keep the complexity down as well as cost. I envision a box with a single knob in the middle for power and on/off and the selections that I intend to offer. Mulitple inputs would not be difficult. This could be achieved with a simple toggle or push button to toggle through relay selected inputs.

Adding a GOOD VC is expensive and not really fitting this products price-point or intent. I am aware that many DACs use bit dropping VC's, but you also need to consider that most new DACs are also 32 bit. With most all data being 24 bit, they are still truly non-decimating VC's.

Sure, a R/C stepper would be great, but the cost of that alone could exceed $1K! My expectation is that the customer will either have a built in VC in their source or a really good passive attenuator upstream of this product.

As for what is old being new again...yes and no. There are many cheap buffers on ebay and Amazon from China. Most are high distortion designs that are intended to add tube distortion. The circuit I am using is very low distortion and wide bandwidth, so while the tube character is there, it is not due to high amounts of tube distortion. The product I have in mind will be versatile and offer the user different options to tailor the tone of their system.

Thanks,

Dan

jjss49

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #188 on: 28 Apr 2021, 02:53 pm »
if you are making it dan, no one who has been your customer will doubt its voicing or its production quality

so comparing to cheapo hyper coloured chinese ones isn't part of the consideration

the musical fidelity pieces are not that though, but certainly, anyone who knows gear would not expect them to sound as nice as what you would make in the modern day

RDavidson

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #189 on: 28 Apr 2021, 03:13 pm »
jjss49, I was only offended that you posted advertisements for old, low priced, crappy, "competitors." I thought this was in poor taste. I am very aware of what Musical Fidelity has put out on the market over the years. Many of us here are aware. So your post with the advertisements came across as a jab at Modwright...like, why pay $1k for a simple tube buffer when that has been done and can be had for far less $? With your further explanation, I understand your intent was not malicious now, but surely you can look back and see how your post came across poorly, right? There's TONS of info written and available online about these old, lesser, buffers from MF and China, so why choose to share eBay ads to make your point? That's all I'm saying.

2 outputs on the buffer would be a great, and I think a simple, low cost, option. 1 output to the main amplifier and 1 output for a subwoofer or two (left and right). That'd be SUPER handy for folks using their DAC for preamp duties.

Rusty Jefferson

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #190 on: 28 Apr 2021, 03:44 pm »
OK, I can see the desire for a VC. I am trying to keep the complexity down as well as cost. I envision a box with a single knob in the middle for power and on/off and the selections that I intend to offer......

....Adding a GOOD VC is expensive and not really fitting this products price-point or intent. I am aware that many DACs use bit dropping VC's, but you also need to consider that most new DACs are also 32 bit. With most all data being 24 bit, they are still truly non-decimating VC's.

Sure, a R/C stepper would be great, but the cost of that alone could exceed $1K! My expectation is that the customer will either have a built in VC in their source or a really good passive attenuator upstream of this product...

Thanks,

Dan
Completely understand. I have several high quality dacs (Lampizator, Chord, Aqua) none of which have volume control. In one system I'm currently using an LTA Microzotl, which is very similar to what you originally suggested building (tube buffer with volume). It has high input impedance and <2ohms output impedance, allows significant tube rolling, is dead quiet, and can drive multiple amplifiers effortlessly. But, it has gain. 6db in it's lowest configuration, and I'd like zero gain for high efficiency speakers. I do think there would be more interest if your buffer had volume, even if optional, and perhaps even at price points of VC choices. Don't want to beat a dead horse though. Appreciate  your interest in members opinions. :D

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #191 on: 28 Apr 2021, 04:22 pm »
Thank you all for your support. I realize that when it comes to a 'tube buffer', there is really nothing of quality on the market and most are the same basic circuit that anyone can make. I have something different and better in mind, obviously.

I want to keep it simple and < $995. It will be sold direct, not through dealers, so the value will be high!

RE VC, it isn't that it would add significantly to the cost, but it would be a volume pot, not a stepper or autoformer based control, etc., as the budget will simply not allow. Having said that, I have access to good and not expensive volume pots that could be designed in, with a bypass.

RE XLR inputs and outputs, there are two ways to do this and both add some cost. If I use transformers, it will add a non-trivial cost. Good transformers are not cheap! I could also design it to be fully differential and this would mean four tubes instead of two. This is the lesser cost way to go. There is even the possibility of designing it in such a way that tubes LA and LB, RA and RB could allow for some mixing and matching of tubes for different sound. I.e. not requiring a matched quad, but rather two matched pairs. One could be warm and sweet, the other fast. It would be a way to adjust the sound and tone.

'Tone Adjust' is a key feature of this design to me. I DON'T mean that it will have tone controls, nor will it have gain. Lastly, no feedback. Feedback and tone controls (traditional) would all require gain. I also don't like to use either FB or tone controls. Rather, with different tubes and perhaps different circuit implementation that is adjustable on the fly, the customer could adjust the tone of the product to suit their ears. I have already shared one way that this could be done.

I think the tube rectifier is key as it also allows a further 'tone tuning'. To be clear, 'tone tuning' does not equate to added distortion or reduced bandwidth!

I think that adding say two inputs and two pairs of outputs could be implemented in the base model as I can see the benefit of this. Perhaps XLR and RCA outs, where the XLR outs are fully balanced? Also fully balanced inputs and RCA inputs. I need to know how many people want balanced inputs and outputs.

My plan for this product is for it to be as simple to use as a connect and forget, setup, but adjustable to allow people to taylor the sound to their tastes also, if they choose. I also don't want any dip switches or anything that requires taking the cover off. I plan for tubes to be fully exposed and the front panel controls to be simple and 'on-the-fly' as our PH 9.0 and PH 150 phono stages are.

Aesthetically, it will be clean and physically slim. I don't know that it will be full 17"W and I would prefer to keep the enclosure height to close to 3"H. It could be set directly on top of a digital or analog source, provided it doesn't need to reject heat. I don't typically recommend this from a noise standpoint, but in this case, if there are not signal transformers used, it could be done. Tubes will be on top and exposed, so all heat will be rejected up and out of the unit.

I would like to see a simple faceplate with one knob in the center, for power on/off and input select. Perhaps one or two other buttons for other features, but ideally clean, simple and uncluttered. This is not a preamp, not a professional mixing device with knobs and switches to adjust. It is meant to be clean, simple and easy to use, but still allow flexibility for the user who wants to experiment with different 'tone'.

Thanks guys, this product is long overdue and the design has left the station!

Dan

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #192 on: 28 Apr 2021, 07:47 pm »
Who wants to be able to use 2-3 different families of tubes in the unit?

Thanks,

Dan

Rusty Jefferson

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #193 on: 28 Apr 2021, 08:13 pm »
 :wave:

Audiosaurusrex

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #194 on: 28 Apr 2021, 11:21 pm »
I love this concept Dan! I own the LX500 that you modded but would love to have a tube buffer for my RME ADI FS DAC. Everything you do brings that tube magic. For me I was never able to get the 225i on my budget but this will bring me closer to tube heaven. So happy to see more affordable solutions! Thank you Dan
René

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #195 on: 28 Apr 2021, 11:31 pm »
Right on, thanks!

Volume control?
Multiple tube option?
XLR and RCA?

Dan

Audiosaurusrex

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #196 on: 28 Apr 2021, 11:47 pm »
For me volume not necessary, it’s a buffer not a preamp sooo IMHO.
Multiple Tube Option -Definitely
XLR-RCA - Definitely
Again great innovation and definitely will fill a void.

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #197 on: 29 Apr 2021, 12:47 am »
Thank you! The VC is still something I am working through. I think that people want it to be a preamp and that is not the intent.

As to XLR and RCA in's and outs, it is a matter of more tubes or transformer coupling.

Thanks!

Dan

The Rang

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Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #198 on: 29 Apr 2021, 06:54 pm »
Sounds like one input only, is that correct?
If so, having two sources (DAC and turntable), is there a way to hook up  this buffer to my KWI 200 and utilize it for both ?

modwright

Re: Quick Product Poll! Tube Buffer with Volume Control?
« Reply #199 on: 29 Apr 2021, 06:59 pm »
I think that two inputs would be a good thing, as well as two outputs. That is easy.

As for XLR inputs and outputs, that is a decision that requires more complex design and added cost.

Thanks,

Dan