Blind Dog Valve Amplification

26/08/2023

I'm selling off some of my stock amps to make space for more. These are mainly Matchless Lightning clones, Vox AC10 style and 18W Plexi-style amps all hand-wired. If you are looking for a bargain, PM me for more info or to come and try at SO45!

25/03/2023

Yesterday I handed over this lovely hand-wired Blind Dog JCM800 2204 commissioned by customer Tim, who back in January year purchased the Blind Dog AC10 SRT featured in earlier posts. Tim specifically wanted this Marshall elephant grain red tolex with gold trim that he had seen on one of my earlier builds. Sorry for the poor quality photo! Below are gut shots and Tim's comments after taking the amp home and putting it through its paces! Thank you Tim for your kind remarks!

29/12/2022

Blind Dog Art Deco 1 x 12" cab ( speaker not included) posted on Ebay, Item no 115656193158. Or PM me. Cystom options and speakers also available.

28/12/2022

Sound clips of Blind Dog's reworked version of the Vox AC10 SRT, inspired by Doug & Pat video review of the 1965 Vox AC10 SRT, of which only a couple of hu...

28/12/2022

BLIND DOG AC10SRT DEMO
Finally managed to get John Swinburn's demo of tasty Les Paul sounds uploaded to YouTube at https://youtu.be/RDzRY4yFYFw. Have a listen! Some clean trem and reverb clips at the end.

Sound clips of Blind Dog's reworked version of the Vox AC10 SRT, inspired by Doug & Pat video review of the 1965 Vox AC10 SRT, of which only a couple of hu...

27/12/2022

For those from Ebay who wanted to know what the 18W Plexi sounds like, I have managed to crudely cobble together a few sounds on the video below. They don't do it justice at all but I will persevere with trying to get some decent recordings!

17/12/2022

BLIND DOG AC10SRT HAND-WIRED AMPLIFIER

17/12/2022

Great review of the Blind Dog AC10SRT posted by John Swinburn of London, England, who first drew my attention to this gem of an amp and commissioned me to build one as a lockdown project (scroll down to earlier posts for more details). John has also kindly recorded some sound clips which I will post later!

12/12/2022

More on the amazing Vox AC10SRT and my Blind Dog version of it. I just rewatched the Doug and Pat video. It reminded me of a few things. First, their sheer enthusiasm for this amp, which they have been using for decades in live shows and for recording. They say only a couple of hundred were ever made and they have three of them which they demo in this video, along with various speaker types.

Secondly, they highlight the radical difference between this SRT model (Super Reverb Twin) and other versions of the AC10. The SRT has four preamp tubes, giving it a higher gain structure than the other models. I was particularly interested in the different preamp valve lineups, all three of the amps tested being different. Stock is ECC83 in position 1 and ECC82s in 2 to 4. My experimentation led to ECC83s in 1 & 2 and ECC82s in 3 & 4, it just sounds livelier!

Speaker type is a matter of personal choice, and their comparisons demonstrate that these amps sound great with anything. My personal preference is for the Celestion Alnico Gold, which is the nearest to their vintage Alnico Silver. Other speakers I have tried it with are the Celestion Vintage 30 and Creamback Neo, also great speakers.

Doug and Pat, while loving the tremelo effect, roundly dismiss the Vox reverb and say they never use it. This because of the ghastly bodged design Vox used comprising a single spring stretched between two ceramic phono cartridges, one as send and one as receive. This was a poor quality solution, subject to noise and microphonics. The Blind Dog version replaces this with a transformer-driven Accutronics reverb tank giving a much more usable Fender-like reverb.

Highly recommend you take the time to watch the video!

Doug & Pat video here

It's been called the Mystery Amp to the amp that never was. It's the 1965 JMI built Vox AC10 Super Reverb Twin head. It's the amp used in every pickup and gu...

11/12/2022

For those of you who saw my earlier post UNRAVELLING THE VOX AC10SRT, I've finally got around to completing a second one of this very fine and rare boutique valve amp head, as featured in the Doug and Pat YouTube video linked below! As before it is hand-wired with turret board construction and features Accutronics valve reverb, a pair of JJ ECC83s, two Mullard ECC82s and a matched pair of 6P14P-EVs (military spec EL84s). It is presented in the Blind Dog trapezoidal head cab, finished in black Tolex with engraved wood front.

This one will be up for sale. I am looking for £850.
Come and try this and my other amp builds by arrangement at SO45 (UK).

Doug & Pat video here
https://youtu.be/alBO_yEn5o4

31/10/2022

Great day at the London International Guitar Show at Kempton Park yesterday with Mike Steele and John Ralph. Looking forward to some interesting conversations about new custom builds. Most popular were the AC10- and Matchless Lightning- style builds and the Art Deco finishes. Catch me on Messenger if you want to discuss new builds to your own specification, or to try out the amps at your leisure in quieter surroundings down here in the New Forest!

08/10/2022

08/10/2022

OUTSIDE THE BOX

I get as much pleasure from creating interesting finishes on my amps and cabs as from playing with valve amp designs and tones. While most of my Blind Dog products have featured traditional finishes using Tolex, Tweed and piping, more recently I have been working on Art Deco styles and finishes, echoing vintage radio designs. This has become possible through using a large-bed CO2 laser which can both cut and engrave woods. Comes in handy for those custom faceplates too.

Best results are obtained using best quality Baltic birch ply but in some cases I use hardwoods too. Intricate patterns take hours to set up and engrave, even with a powerful machine but there is virtually no limit to designs that can be used, so let us know if you have something special in mind.

Pics below show some of the finishes and steps involved.

07/10/2022

POWER SCALING

The age-old issue for the electric guitarist is how to tame volume while retaining the harmonically rich tones of overdriven valve amps. While modelling amps offer one option, for many these simply do not hit the Shangri-la of tone offered by valves. Various types of power-soak attenuator allow the amp to be wound up to eleven at room friendly volumes offering one approach. Another is to lower the HT voltage fed to the valves, causing break-up at lower volumes. This is known as 'power scaling' . Power scaling uses a semiconductor circuit to control the voltage applied either just to the power stage or to the whole amp. This is most simply achieved in cathode biased amps. I fit power scaling to certain Blind Dog amps on request, typically in the under 25 watt amps (which can still be very loud). This can bring the output level down to 1/4 watt or less. Bear in mind however that speaker distortion also contributes to tone at high volumes, and also the audio response of the human ear is also affected by loudness. It'll never sound quite the same, therefore!

05/10/2022

MARSHALL CLONES AND DERIVATIVES

There's nothing like a Marshall for that '60s British classic rock sound we associate with Hendrix, Clapton, Kossoff and countless others.

My first Blind Dog Marshall build happened many years ago when a friend loaned me an ex- lab equipment mint 1963 JTM45 that he found dumped in a skip at his workplace! He kindly allowed me to take it apart, photograph and measure everything about it. I built three blonde Tolex replicas from that amp, which I believe are still doing the rounds.

Since that time I have been asked to build all the various Plexi variants, JCM800 2204s, and 18 watt Bluesbreaker type amps. Builds this year pictured below have included a 1970s 50 watt lead (black, upper), a JCM800 2204 with 1x12 Vintage 30 cab (red) and 18 watt non- tremelo plexi-style amp with power scaling (black lower).

04/10/2022

IN TWEED THIS AUTUMN?

Who doesn't love the look of a nicely aged Fender Tweed bringing back some '50s nostalgia? Plasticised replicas simply don't cut it - it has to be the real thing, shaping up like a well- cut jacket from St James!

Over the years I have often been asked for Tweed finishes and I must admit it my favourite form of covering to apply, though a little costly these days. Typically it is applied to Fender 5F8 Low Powered Tweed Twin and 5E3 Tweed Deluxe models. Basic application of the fabric is straightforward but the fun starts with the coatings, which give a more authentic vintage vibe. I use the traditional method using shellac varnish (as used in French polishing). To achieve a good finish, up to eight coats are required, lightly rubbing down with wire wool between coats. A deeper gold-bronze colour is achieved using the darker button lacquer. Some customers like the more distressed look. I was once asked by a blues cigar-box/ harp player to add some beer glass rings and cigarette burns to give his act some atmosphere!

The pic below is of a 1 x12 combo version of the Dennis Cornell designed Stinger 10w Class A amp. I had some Tweed on the shelf and just had to do it! Come and see and hear it on the Blind Dog stand at the London International Guitar Show.

03/10/2022

KEEPING IT LIGHT

Much as we all love a traditional big combo, who wants to lug an 80lb monster up the back stairs to their gig? Fine for touring bands with roadies but I am increasingly asked for smaller, lightweight back-friendly heads and combos. So, what are the secrets of achieving this without sacrificing tone?

The main culprits that make a valve amp heavy are the transformers and chokes, the speaker ( in a combo) and the cab itself.

There's not much we can do to reduce output transformer weight - it is critical to the tone of an amp. This is partly true for the power (mains) transformer too. However, there are exceptions, for example toroidal transformers can be lighter than their laminated equivalent and I do occasionally use them in Blind Dog amps. Another trick where valve rectifiers would traditionally be used is to replace them with a sag circuit which replicates the internal resistance of a rectifier valve responsible for sag. This takes away both the weight of the rectifier and its base and reduces the mains transformer size and weight. I use the sag circuit in my Matchless-style 15 watt (based on Lightning and Spitfire) and a few others. It is also much more reliable than valve rectifiers.

The choke can be another heavy chunk of iron. In my lightweight amps this is replaced by a circuit know as a gyrator. It has identical performance but adds only an ounce of weight.

Speakers are very much a matter of personal preference and what voices well with the amp. While I am a big fan of Celestion Vintage 30s, Greenbacks and Alnico speakers, the lightweight Neo Creambacks work really well in my Matchless- style combos.

Finally, cab design can make a big difference, apart from the obvious use of separate heads and cabs to improve portability. My recent builds have used void-free 12mm Baltic birch ply as standard, going up or down in thickness according to strength requirements. Generally I prefer to use the lighter grades for speaker baffles but this depends on the weight of the speaker to be supported.

Below are listed the weights of some Blind Dog amps. Remember, if you use a small amp you can always mic' it up.

Blind Dog Thunderbolt 1x12 Red Combo...28lbs (pic below)
Blind Dog AC10 EF86 2 x 10 Combo....23lbs

02/10/2022

AC10 EF86 BUILDS

After starting the AC10 SRT project, I had a desire to produce a boutique version of something like the AC10 with just an EF86 preamp, as I have always loved this in the EF86 version of the AC30 and I'm also a big fan of the Matchless DC30, which has an EF86 channel. After some experimentation and fine-tuning, the Blind Dog AC10 EF86 emerged and sounds fabulous, with classic vintage British tones. I now have head and 1x10 combo versions in my trademark Art Deco styles, as well as a small head in snakeskin Tolex. All are hand-wired using turret board construction. The combo version features a Celestion G10R30 speaker, which nicely suits the voucinf of this amp.

Come and try them out on the Blind Dog stand at London International Guitar Show (Kempton Park, 30th October 2022).

02/10/2022

01/10/2022

UNRAVELLING THE VOX AC10SRT

After the 1st lockdown one of my customers asked whether I would be able to build a copy of the Vox AC10 SRT (Super Reverb Tremelo). I hadn't come across this model, not surprisingly as only a few hundred were ever made, back in the '60s. The magic of this amp is revealed in a Doug & Pat podcast on YouTube (https://youtu.be/alBO_yEn5o4). There have never been any reissues of this amp although one boutique builder in the US has had a go (Henry's Amplification).

Given this challenge and spare time during lockdown 2, I set about building one. There were two main challenges. First, the published circuits found online contain serious errors which I had to sort out. Secondly, the reverb used a crude and unimpressive arrangement of two crystal phono cartridges (remember those?!) connected by a spring- apparently because Vox didn't want to pay royalties on the vastly superior Accutronics design! I went on to build a prototype version, which my customer pronounced himself delighted with. I am now currently halfway through a final version. This just consolidates the various changes that I made on the way, resulting in a neater board layout but otherwise the same.

The Blind Dog AC10SRT is a close clone of the original Vox version, apart from the improved spring reverb setup. It features 4 preamp/PI valves and 2 EL84s in the output stage, giving a generous 10 watts. I used a custom-wound Demeter (UK) power transformer and period- correct ClassicTone paper-wrapped output transformer. I did not exactly replicate the original trapezoidal head cab design but tried to reflect this in my version.

Hope you like it!

(Pics below show the original Vox AC10SRT and the chasdis and finished Blind Dog version)

30/09/2022

What is a hand-wired amplifier and (why) is it a good thing?

All of the early classic valve (tube) amplifiers pre-dated modern printed circuit board (PCB) designs and were hand built on eyelet boards (e.g. Fender), turret boards (Marshall) or used point-to- point wiring (in which components are stretched and soldered between valve bases, pots and other contact points without the use of boards).

Almost all mass-produced amplifiers use PCB construction. This method is far more cost effective and generally provides good performance. However, if you look at the populated PCBs in the commoner production amps you will notice that component sizes are generally smaller than in hand-wired amps. This is because they are built to a price using 'just enough' principles. When these amps fail, it is often because a resistor or other small component overheats, charring the board and burning conductive tracks.

Point-to-point wiring can be good in simple designs but quickly can become unmanageable in more complex designs, with risks of stray signal causing feedback and other problems. It is not a common technique in boutique amps but works well when done properly. It is the least cost effective method.

Turret board and eyelet board hand-wiring are most favoured by boutique amp makers and, in my view are equally good. Both lend themselves to small- volume production and I favour either type in my amp builds. They allow larger, generously rated components that always run cool and easy swapping out of components to explore tonal changes. In other words, reliability and flexibility!

Pics below show Blind Dog gutshots with eyelet board above and turret board below.

08/11/2021

Please message to enquire about our current range of custom valve amps and cabs, from 10 watts to 50 watts, British and US styles, separates or combos. Including our new custom-crafted art- deco designs!

08/11/2021