300b lovers

Not to tread on any designers toes in any way, more a testimonial to the impression a well thought out 300b design can have. 

I have heard 300b Valve Amp's over the years, mainly SET with low Watt Output.

I have liked the vocal and simple acoustic music when replayed through them, but in general have not got too attached to these types of design.

Recently I have been auditioned a Tim De Paravicini design PP 300b that was in production 30ish years ago. 

A friend has purchased it, who has a system I know very well and have been used to hearting Neurochrome SS Amplification and VAC Valve Amplification. The Amp' was given a pre-heat prior to my arrival, the impact the the TDP design 300b Amp has made on the presentation was quite instant. I was aware something quite special was being used and become very contented with hearing a 300b Amp' in use that were really worth making a reference to, hence I am producing this post.

The Amp's owner has informed me the Neurochrome and VAC Amp were now most likely to be sold, as they do not foresee the need for them any longer.

There is in my opinion a a new satisfaction in place. This is so far achieved without a Tube Roll, or a swap out of some very old Cap's. 

A PP 300b Amp can really work for those who have struggled with the Tubes used as a SET dsign.

Like @whitestix I am quite comfortable with my very limited understanding of 'Math' for Electronics and 'Hands On' practical exercises with Electronics, even though the latter is easier to comprehend.

The above has never been a limitation or a constraint for me in relation to having Devices produced for Audio that are Bespoke and unique, as is the Design of Amp's under discussion in this thread. I have created relationships with EE minded  individuals that are very adept, and one relationship/friendship extends back 30 years and I still contact the EE a few times a year and send a Bottle of Drink for them in the New Year.

The Math is one thing, how to utilise the Math and adopt it to be used for the Practical Exercises being undertaken, 'will always be a better undertaking', when a time served experienced individual, who really has a understanding of how to interface their design hooks are doing the Math and Circuit Design.

I have 6SN7's actually 'Half 6SN7's' in a Driver Stage on 845 Mono's. I have been fortunate to have had a variety of these Tubes from modern to vintage tested for being matched pairs. These have then been used for Tube Rolling and as the subjective evaluation, I have become very attached to the Vintage KR VT 231 Black Glass for the SQ when the perception of a lean Bass and projected Mid and High is the desired presentation. If a Richer Presentation is desired, the Vintage Sylvanias do this, to various degrees, even though some will swear the details.

As a subjective evaluation I have found that the modern Tubes EH and Genalex have proved good for a period of time, a distortion can be detected to develop and even though not too much of a detractor, it is enough for me to want to end the use of the Tubes when it has been detected.

I have been extremely happy with what I have learned about the use of a 6SN7, I have also found the Tubes I am Wed to.

Additionally, due to the rarity and costs associated with vintage tubes and then the concerns for a accurate matching, I have looked at other modern alternatives and there is a Linlai Thread on this forum that presents a very positive assessment for this Brands Tube. 

As a Tube Roller and attendee of other Tube Owners rolling experiences, I am very aware a magic can occur as a result of a change of a tube. When Don's 300b design is up and running, I am sure there will be a time when an owner will become curious and the stock 6SN7's are to be swapped, there is nothing to suggest differently, that a Valve might be discovered that really 'hits one out of the ball park' for the perception of Amp's performance.             

When individuals that have a keen interest in Audio and are time served, make a discovery that is able thoroughly impress, there should be little doubt as to the devices capabilities when properly partnered with supporting ancillaries.

Even though these Amp's are yet to receive a name, I know they will capture many when encountering them for a Demo', and a fair amount of talk should follow on. I know this experience personally through using my system for Public Attended events where demo's of my system and multiple other owned systems have been exhibited for demo' purposes.    

I wish the Amp' was available for one of my Local HiFi Groups future get togethers.

I'm sure all the owned and respected Sources and the selection of Quad ESL Speakers will be partnered to it for numerous hours of indulgencing in the delights it can conjure. 

My PP 845 Mono's are produced with a optimised performance for the 845, they are Low Wattage approx' 25 Watts when the VU Metre at Biasing is set to 12.5, I have been informed I can push the Watt Output Up if I increase the Bias, but the Trade Off is a reduction in the Head Room, in the past I played with Bias, but the Headroom when perceived is quite addictive as a trait of the Amp.

These Amps have Hand Wound Output and Power Tranx's, the designer/builder has informed me recently, that even though there are increased options for Tranx's since this Amp' was designed, there is not an off the shelf winding that they are aware of, that is readily available to suit the Amp's design.  

When I was having a Bespoke Valve Input/Output Phonostage Built for me.

The designer builder was running two builds parallel, with the only differences being one had more RCA Inputs and my one had a Single RCA Input.

The Designer Builder invited me to listen once more to the design, but I could not get my head around it, there was still too much perception of weight, which was a a assessment put forward during the demo's done prior to what was supposed to be the final demo' prior to completing. 

I told the designer/builder, it was time to introduce Foil Resistors and Alternative Cap's. After some toing and froing, we got there in principle. Z Foils and a selection of Copper Foil Cap's was bought in.

The impact these had on the Sonic was from my assessment something very very special, even the designer /builder was on board and had their eye on this as a Upgrade Package on the Phon's if they were to be produced in increased numbers My later investigations which resulted in the addition of Vintage Tubes selected as a outcome of Tube Rolling experiences, was the addition that is the Cherry Garnish on Top.

The Tuning/Tweaking has the capacity to produce a sonic that is very different in the attraction/likeability generated to a earlier version. 

I use Tubes that also run quite hot, the Amp's these tunes are utilised in are positioned in free space away from other Structures within the room.

I have in the past owned a Portable Air Conditioner Unit, that produced Icy Cold Air, this has been reserved for use when the External Temp's are getting up to the +25 Centigrade to help with sleeping. When using the room the system is set up in during these periods of high Temp's, I have never felt there was a need to run the Portable AC Unit during a listening session.

If increasing Room Temp's are a concern, as a result of a Tube Amp' being used, and a Cooling Device is at hand, cooling the Room in advance of the listening session is certainly going to cool the room and not impact on the Sound being produced. 

My cautionary advice to an individual interested in using Tube Devices is no different to the advisories I was given many years past, which is to make sure there is always 'eyes on' the devices in use for the bulk of the time they are Powered On, and have a revisit shortly after being Powered Off. After approx' 30 Years of using Tube Devices, I have not had a concerning experience, only the oddity of a electrical glitch, a spent Valve or a blown fuse.     

In relation to what @lynn_olson is sharing about the listening experience being a stimulus and the impression that can form resulting from the stimulus being encountered.

I have on many occasions been an invited party to offer a 'pair of ears', and to offer a assessment of how a New Design is evolving. There are devices experienced that have been built in parallel and a early prototype is kept as such, with a second prototype undergoing changes to see where there is improvements to be discovered. This method is sort of similar to a modern Photo Editing Software Tool where at the Click of a Button, the before image is immediately viewed.

There are also devices that are sole builds and the experiences of receiving demo's a a result of changes being made are in theory a variant of a previous device used. Much of this is reliant on recollection of previous experiences. This as a method is also quite dependent on the demo's not be too fart apart and the other devices in the system being consistent and not being exchanged.  

Relating to the first method, it is much easier to identify if the ongoing work, is able to create a improved impression. It is also much easier to suggest trying out a different supporting ancillary as the two Prototypes at hand enable a very useful evaluation of how the exchanges interface with other ancillaries.

Relating to the second method, I find written records of how the demo' was able to impress and sharing through discussion where it has been perceived attractors/repellents are present is a constructive approach. Follow up demo's usually reveal differences are developing, and where there is betterment being perceived.

There will be a time that a divisive situation evolves, as individuals are unique in their preferences for a sonic. The Range of Attraction for Lean/Transparent through to Overbearing/Muddy is what sets all individuals apart. No one can tell an individual where there attractors/repellents are in the scale, they choose these themselves.

When it comes to buying a Device designed/built by the hand of a Trusted EE with Time Served Experience in producing audio devices, it is not just the realised product being bought into, but the designer/builders philosophies for audio reproduction and their IP, the hooks utilised to create the sonic on offer. 

It is no secret such IP is classed as a asset, is their not Circuits that when, investigated there are no values to found on components, the printed info is removed to protect the design from being easily plagiarised.        

A Friend who helped me source my Valve DAC, at one point was into heavily modifying a few CDP Models from the Sony Brand.

It was my introduction to these Modified CDP's being demo'd through Bespoke Built 300b mono's and Horn Loudspeakers, that were the first digital sources to arouse my interest in digital as a source.

I heard these in all their evolving guises and was even able to have extended home loans, which ultimately ended up with my decision to have a Digital Source added to my system.

One Sony Model had the Highest Quality Caps and Resistors used and lots was going on with how the Valve Stages were designed as well.

There was 'creme dela creme' mod' to be carried out that was inclusive of the use of OCC Silver Wire purpose produced Tranx's. When these were incorporated to the design, there was no Run In period that could help, the sonic and attractive impression that was recognised, plummeted from presentation, the overall presentation was perceived as forced and in ones face, quite unattractive and certainly not able to create a settling down and softening of a mood. 

When this same individual producing the CDP's had his GM70 Mono's built. I was again being asked to assess them with him. I thought they were sharing noticeable traits in how I recollected the 845's were able to present.

The GM70 owner convinced themselves there were more to be extracted and carried out Mod's on the Amp's. I was again asked to visit and take part in a listening and assessment session, to which I agreed to when the Amp's had a minimum of a 100 hours on them in their new guise. In my view, the Amp's had become lesser, there was from recollection, some of the earlier impression made, now at a place where I was trying to work out where the changes were and why the presentation had lost much of its allure.

As said earlier, when carrying out such demo's with others, there is a time when the opinions will be differing, I held my tongue, and agreed that if the changes made had been satisfying to the end user, then this is the ultimate goal, I politely made it known I had recognised changes had occurred. 

Who is this @edisoncarter, whom feels they were overlooked when visiting a Room, that was on all accounts buzzing with excitable interest and inquiries.

Most who arrive at such an atmospheric place, would humbly inquire about when music was to resume, maybe even ask, if I return a little later could I hear a track of choice. I don't know how the @edisoncarter made their approach, I was not their.

The follow up communicating of their interpretation of their experience has been presented in my observation with a Forked Tongue, this is pretty much self evident by the content of the last comments made from @edisoncarter 

"You want my unbiased view on this thread? Never seen one so dedicated to shilling allowed to go on and on. Free advertising. Must be nice."

If this is the case as a casual observer of this Thread and then becoming influenced enough to contribute through making posts, is suggesting I have been complicit in Shilling a Product presented by a few individuals I have never met, or never communicated with until this very Thread.

Have the individuals behind the product got their correspondence absolutely honed to the point where they are able to compel others to do their bidding, either of the above are all BS, and not reality.

You want my unbiased view, "well done to 'Cutting the Head of the Snake'.

Fortunately it is only one's Pride hurt, @edisoncarter has engineered their 'What about me Moment'.

It does look like the Reputation of those that put in the real Sweat, Blood and Tears remains intact, credit where it is due.

Hopefully my 5 x referencing @edisoncarter in one Post has been a Band Aid for the Bruised Ego incurred.

I'm feeling like this following experience, might be a description that is accused of being a Shill, for a Certain Brand of Stepped Attenuator, so I will tread carefully.

A Certain Brand of Stepped Attenuator, referenced on the 25-06 @ 6.13 am, is a device I am quite familiar with.

I have been demo'd it as a Upgrade VC in a few Pre-Amp's over the past 5 Years.

Most recently a Pre-Amp' I get to sit in front of regularly had undergone exchanges of a few VC's over course of a Year, and the Pre Owner thought they had made a Good Choice with a DACT, which most who had heard it in use was in agreement.

Not too long ago the itch was scratched and out with DACT an in with said VC.

The difference the Part made was Night and Day, the new an impressive insight into the recordings was immediately perceived and as the session went on there was too many attractors detected and spoken about, to even consider the DACT might be worth a revisit.

I am not poo pooing the DACT, I have heard them as a Mono Device used a Balance Control on a 300b Monoblock Power Amp and they have been superb, when used as a VC on this set up. I also own a Brand New unused Stereo DACT 

The said VC, has just shone out as belonging in this Particular Pre Amp's Circuit.

I am all in, 'in this thread', it has catapulted me back in time, to when I was involved in discussion with a EE, who was helping me achieve something quite unique as a Valve Power Amp'. A very enjoyable period and wonderful to be reminisced.

The Bruised Ego is certainly not pointed at any regular contributor to this thread.

It is specifically for @me! me! me! carter, who felt the need to declare two designers as ringleaders and many/all Thread contributors as accomplices to a 'Sting'. 

What a Bungalow this individual has shown themselves to be.  

I now have a VC, which comprises of two matched Stepped Att' VC's for the mono block Pre-Amp' Design .

These are produced by a friend of mine specially for my Pre-Amp's Design only.

The usual ones produced are for my friends Buffer Pre' Design, I was requiring ones that are with a different measurement at 50K.

The Pre' Builder has expressed his satisfaction with them, and has heard them compared to a very similar Pre-Amp' design that has the other VC I referred to. 

I got a little side tracked with this thread, I'm back into the 300b theme .

I did not share, that on Sunday 25-06, I was able to attend a demo' of a 'new to me' system, which has Klipsch Jubilees as the resident speaker.

The resident system in use was quite special.

Following the Lunch recess, a friends P-P 300b Power Amp' was put to use.

The 300b is a late 90's model of which Tim De Paravicini has an input to the design. This Amp is now overhauled and a few circuit tweaks are carried out.

The system owners reaction to this Amp' was immediate, the Cheshire Cat Grin lasted for many tracks.

All attendees were thoroughly impressed by the way this Amp' interfaced in this system and it really shone out for its attractive traits.

That is not the whole story, the systems pre-amp was swapped out for a Bread Board mounted, part completed pre-amp build.

This addition of the New Pre-Amp had a substantial impact in conjunction with the 300b. 

My take is that the design of the 300b in this Thread, has another 25ish Years (50 Years Combined) of experiences of Two Amp Designers, put to use, to help create this latest design.

I would get great pleasure from receiving a demo' of these mono's, to see where there are sonic traits that stand out as being more of a attraction and very much wanted to be kept.   

@lynn_olson Another nice to read recollection of a History of Amp Design and the connections made over the years 'pardon the pun'.

Some of the content once more Jogs my Memory.

I recollect my 845 Power Amp designer/Builder, requesting that I keep him in the loop if any EE support is required during ownership.

Again as a recollection, it was made known there was their own Hooks in the Circuit Design, that was beneficial to creating the perception the sound produced was transparent.

I am now wondering if this was a similar description to your own, where creative thinking has been used to produce circuits with the potential to align the SET - P-P sonic where there is seemingly a mimic, rather than a contrast.

I am due to spend time with the EE, in the not too distant future, My Balanced Pre-Amp will soon be complete. Which will then be passed onto the EE, who is to work on the 845 mono's, whare a Balanced Design is to be produced, with the Single Ended option retained.

I have been a friend and loyal to this EE's Services for more than 30 Years, I think that has proved sufficient as a 'NDA' about his early works. 

As an aside, a few individuals have asked to see inside the Power Amp. One  individual wanting to make a mark in the audio world, who I knew quite well, and have not at present not communicated with for quite some time, attempted on more that one occasion to be allowed to take the Power Amps Base off and see the Circuit.

My not being supportive, at one time lead to my being threatened that I was on my own with any future EE concerns, if l did not accommodate the request. For other reasons relating to this individual, I am on my own 'Hey Ho'. I'm pleased I 'stuck to my guns' and honoured the Designer /Builders request , and I certainly am not on my own where EE support is needed.

Lets hope owners of your New Amp design, do not find themselves meeting Pirates scheming to steal another's IP.       

When time served EE's who have leaned toward and made Valves a Circuitry, they have dedicated themselves to, there is a lot on offer under the hood, that should be very reasuring.

As for reliability, my Amp's have been on the Oscilloscope for numerous Hours/Weeks prior to them being released to me.

Never have the Amp's in all the time of ownership needed to be returned to the Designer/Builder EE due to any change in their performance from general usage.

I do have a Balance Pot' that I have damaged during Transit coming home from a public attended event I exhibited at, they were incorporated to assist with correcting Psycho Acoustics.

This will be checked out when the EE, has the Amp's for the circuit change, where a Balanced configuration is to be added.

I am thinking these Pot's could now be removed?, as the Mono Pre-Amp's, which are my end game keepers, are each with a VC.    

Electronics Engineer (EE)

Volume Control (VC)

For me and the amount of Typo's I keep making, it would be great if I could abbreviate a lot more words.     

On the subject of Linlai, there are 6SN7 Tubes available from the Brand that have received a strong support within this forum.

These Tube Types from Linlai might be a Upgrade Tube worth considering at a later date of Amp' usage.

@lynn_olson Another topic of discussion that has been undertaken by myself recently.

Note: As stated previously, I am no EE, I discuss notions with EE's and EE minded people.

The recent discussions taken part in, has been about the signal travelling through the audio system with as little of a interruption or diversion as can be put in place, with the value of such a approach, being that a direct signal is able to be produced as sound with no loss of content, however miniscule, resulting from an earlier manipulation of the Signal Path.

It was strongly suggested, a later arriving signal (it is going to reach the speaker) can be a info that when finally processed to a sonic, can be perceived as having a effect on the content of the produced sound, such as a smearing/masking of a particular dynamic, detail or frequency extension.

A demo' was also carried out to assist with my helping understand this at a very basic level, and I would settle / will be settling for the measures shown to help reduce the effects of what is claimed to be a delayed signal.

In the case of the delayed signal, it was made known both circuit design, topology and component selection can all be a contributor.  

In the case of the demo' it was quite obvious that at certain places within the replay, there was a Vocal that was more comprehensible and certain notes were sensed as being a rendition that had attained a step further to being a more honest presentation. 

When I read your post, it does look likely to myself, through your circuit design and time spent voicing the sonic, that many of the items that were 'above my head' to address at the time of my discussion are addressed in your 300b Amp' Design. 

The description certainly prompts the idea, that it would be a real pleasure to be able to be in a room with this 300b design one day.       

There are now over the past few months arrived Three 300B Power Amp's within my Local HiFi Group.

Two are from the Designs done by TDP and Andy Groves for World Audio Designs, One of these Two has an upgrade which I believe has Interstage Transformers.

The other is a design from a 'Heart' of Dutch Origin.

I am now becoming re-familiarised with the 300B sonic.

With the recent experiences and the knowing there are certain designers early in their career knowledge been applied to the Amp's, it really does make the idea of listening to the Amp's being discussed in this thread, a experience to be had. 

Who knows a Pair may one day be on the UK to be demonstrated.   

Hi Don, I have heard a VAC Amp' within the UK, one of the earlier models is owned by a HiFi Group Member who owns a 300B.

Another newer Model VAC is also owned by a Group Member, I am yet to be demo's this one.

I have heard Modwright as well other Brands that are not with a dealer distribution, it is not too strange for products to end up in the UK without the supporting networks behind them.

There is a fair amount of UK Audio Enthusiasts who are willing to look far and wide for their entertainment to be satisfied. 

I have not inquired to the VAC Owners if they are using their Amp's with a Step Up Mains Tranx, or with any other US Imported Audio Ancillaries I have been demo'd.

I am a listener first and foremost.

The offer of the Prototype Amp's will be a great temptation to somebody, the Pedigree of the EE's and made known design intent behind this design alone, should be enough to convince a special experience is to be had. The reports of listening experiences to be found within this thread can only but reinforce, the idea of the purchase being very worthy of a consideration.

In the UK there are excellent Third Party support services for Electronics Support in both Valve and SS, these services are able to be found across the Country. The Services are not unreasonable in their costings, I have only ever seen the waiting time from certain services being the cause to search further afield. I do believe that the the notable trust that has been placed in these very services, along with the idea that receiving EE support is not being too much of a difficulty to achieve, is an instrumental factor in the making way for rarely seen items of Audio Equipment arriving in the UK from a variety of Countries where products have not got a UK support network.

As for overseas shipping, there are lots of Chinese Origin Audio Equipment arriving in the UK, especially Valve Amp's, of which some are requesting multiple £0000's to acquire. I am yet to have seen any horror stories about the Quality of the goods , resulting from their Transportation.

I myself have imported many items of Audio Equipment from Japan and over approx' 10 years, have experienced two incidents where goods arrived with a damage that was not as advertised.

Either a undeclared damage or transit damage was received ? 

I will keep looking in on this valuable thread.  

Any inquiries to purchase from the UK as of Yet?

I'm very much hoping their is a build thread for the Speakers to be designed.

This is an area I am progressing into, as I have recently on a few occasions heard Speakers that are a a bespoke design and are as a end sound, what I believe are a challenge to my ESL's.

My personal preference for a Speaker does seem to have changed and a curiosity is now taking hold.

Even the idea of modding owned Cabinet Speakers and attaching Internal Wiring to a Drivers Voice Coil as suggested by another Speaker Builder on here, has my curiosity and is intended to be experienced when advisories are offered.