Reslo Microphone Documents

Reslo PR ribbon microphone

Here are a bunch of scanned information sheets published by Reslosound for various dynamic and ribbon microphones in their range.

Reslo RB information sheet
Reslo CD information sheet
Reslo VMC information sheet
Reslo CR information sheet
Reslo PR information sheet

Reslo Beebs in action with Layla Lane

Pop duo Layla Lane kindly shared their video of their cover of 'In My Life' by the Beatles, which which extensively used a Reslo RB microphone with Xaudia's 'Beeb' upgrades. 

The guitar, piano and all the vocals were recorded with the Beeb connected into an Ampex 350 preamp and Urei 1176 compressor. You can read more details about the recording at their youtube page.

Layla Lane are Heday Ikumo and Valerie Stern, who together have written music for Coca-Cola and Mello Yello commercials, recorded a song for the Ashton Kutcher film Killers, toured Japan, and produced/wrote songs for big Japanese artists such as Sunplaza Nakano-kun and Yoko Oginome.

Beebs in Action: Majetone calfskin drum heads

I have said many times before that we have fantastic, creative customers, and it is always nice when someone takes the time to share what they are doing. Sometimes their stories are amazing!

James Yates makes custom hand-made calfskin and vellum drum heads, under the guise of Majetone Industries.

Here's a video clip of James playing his drums and skins, recorded using two of our Reslo 'Beeb' microphones as top & side mics in a Glyn Johns arrangement, along with a CAD M179 in cardioid in front of the kick drum.

I think these really do sound fantastic, with a classic yet contemporary tone. I could imagine these sliding very easily into a mix without need for much processing.

You can find out more at the Majetone Industries website.

Review of the Reslo RB by F.C. Judd

Here is a scanned review of the Reslo RB miniature ribbon microphone,

The review is written by Fred C. Judd, who was an early champion of both electronic music and DIY audio electronics. You can hear and buy some of Judd's creations at this bandcamp page.

This article arrived with a microphone but I am unsure which magazine it was originally published in. Perhaps "Amateur Tape Recording", of which he was technical editor. If you know more, please let me know.

Reslo MR1 manual

Here is a scan of a 'manual' from 1973 for the Reslo MR1 ribbon microphone, which was the successor to the popular RB model.

I say 'manual' - really it is just two sheets of printed A4.

Reslo Dynamic microphones

Reslo are of course best known for their ribbon microphones, particularly the RV and RV models, However, it should not be forgotten that over the decades they made many dynamic microphones, and even some condensers too.

Reslo VMC with base station

The earliest Reslo dynamics seem to be the VMC and VMC2, with the initals standing for Velocity Moving Coil. These had a big heavy permanent magnet and a paper diaphragm, and are really rather lo-fi devices. These two models are more or less the same inside, although the VMC was hard-wired, and the VMC2 had a new grill and an output plug.

Reslo VMC2, with output connector.

In the late 1960s Reslo made a range of more modern light hand-held dynamic mics. The UD1 used a Japanese-made capsule which sounds rather good, of comparable quality to the Shure mics of the era. I have seen transformerless 200 ohm models, and also a dual output 30 & 600 ohm version with a transformer in the body to convert the impedance.

Reslo UD1 microphones

The UD1 was apparently used by Bob Dylan at the 1969 Isle of Wight festival!  Here is an advertisement scan from the Reslosound blogspot….

The advertising also mentions a high impedance model, although I haven't come across one yet.

Some of the UD1 mics were hard-wired to the cable, and it was also supplied with a Reslo connector, and later a 3-pin din plug, with different impedance options available through the different pins. They are wired like this, with one side of the capsule and transformer primary wired to the output socket.

In addition to the UD1, there was a short stubby version that used the same components, and would often have been used with a gooseneck adapter. Pictured below is also a smaller dynamic mic for use with a tie clip.

These models appear to have been replaced in the 1970s by the Reslo Superstar range, which were essentially the UD1 with an updated body and grill. The Superstar was supplied with a DIN plug - I have converted this one to XLR.

Reslo Superstar 80 dynamic mic.

SJT, May 2014

Reslo Beeb Commando!

Here is a custom edition of our popular ‘Beeb’ modified Reslo ribbon mic. This is the first, and so far the only one we have made in these colours.

Like all of our 'Beeb' mics,  this features an upgraded 300 ohm output transformer, new ribbon and XLR socket. This special edition as well as a switchable high pass filter inductor to balance the proximity effect when used close to sources.

The custom camouflage colours makes it suitable for undercover operations, and even better for guitars and drums!

MOTM: Reslo NC-RB Lip microphone

Our Microphone of the Month for April is this rare oddball from Reslosound: the NC-RB.

This was Reslo's attempt at a commentator's lip microphone, and appears to be cobbled together from spare RB parts. The upper body and head are from an RB, but the head is rotated through 90 degrees and screwed to another chopped-down head.  The lower body-stroke-handle is a straight aluminium tube with a switch which terminates in a normal Reslo output socket.

Inside the head is a rotated  RB-style motor.  The magnets face the speaker, to provide some pop protection for the ribbon at the rear.

Behind the ribbon I found this metal baffle, which should control the pickup pattern and tweak the frequency response. There is also fibre glass and felt wadding for more protection.

Overall it is a strange little mic. The ribbon runs horizontally, which is generally considered a bad plan as, if it sags, it will droop into the metal pole pieces. They must have been a way of producing a lip mic without the expense of re-tooling for a completely new design. I have only ever seen this one, although I know of a customer who owns another.

What does NC stand for? "Not a Coles", perhaps?

'The Beeb' Reslos - also in black!

It is time to down tools for the holidays - this year we are part way through preparing a new batch of modified 'The Beeb' Reslo ribbon mics. The Beebs get a new ribbon, new transformer and XLR upgrade, along with a few other small tweaks. These will be available in January.

This batch now have their own metal badge, which looks great. In addition to the usual chrome and hammertone mics, we also have some rather smart looking black microphones, which have a tough powder-coating finish.

The sound is still the same :)

Reslosound VMC2 Velocity Moving Coil

Here is a nice looking Reslosound VMC2 microphone, successor to the VMC, which (probably) stands for Velocity Moving Coil.

Reslosound VMC2

As far as I can tell, the only real difference between the original VMC and this VMC2 is that the newer model has a slightly different grill, and a three pin Reslo output socket instead of a fixed cable. Inside, both mics have the same heavy paper diaphragm and coil.

Reslosound VMC2

The badge proudly declares that this specimen is a low impedance 15 ohm model.

Reslosound used a fibrous paper to manufacture the diaphragm, and the coil is simply glued to the paper tube at the rear. In fact the technology looks very similar to early speakers.

Reslo VMC2 coil and diaphragm.

When I plugged it in, the mic gave a very lo-fi sound - even more distorted than one would expected for this era. On investigation, there were some metallic particles sticking to the diaphragm, preventing it from moving freely. The paper cone had also become detached from the diaphragm.

Diaphragm from a Reslo VMC2

The remedy in this case was to carefully unsolder and lift the diaphragm and coil. Then I used a magnet and paint brush to flick and drag the dirt away, both from the diaphragm and from the magnet below.

Reslosound VMC2 magnets

Once the obstructions have been removed, the cone was then lightly glued back using some clear nail varnish, and then replaced in the magnet gap, ensuring that it was centred and free to move. This greatly reduced the distortion.

In use, the mic is slightly boxy sounding, with a steep roll off at the bottom end and some dramatic peaks and dips in the response. It very obviously sounds like an early dynamic mic!

Reslo VMC with base station

For comparison, here is a Reslo VMC with announcer's base station. Note the difference in the grill, with five horizontal slats, as opposed to three vertical.

Reslo microphones in disguise

Reslosound sold numerous microphone models under their own name, and also made microphones for other brands. This Reslo RV was made for GB Equipment Ltd, and has a funky maroon logo on the top.

This one is labelled RVH - the 'H' means high impedance output.

I have also seen and serviced RV models with a Philips badge.

VOX badged Reslo RB

The common Reslo RB models were also sold under the VOX and GEC brands. This Vox mic is identical to the Reslo badged model, apart from the badge.

GEC badged Reslo RB

The GEC mics are painted black and given the model number BCS 2378, but it is simply a Reslo
RBS.

In addition to these re-branded models, many Reslo mics were sold as parts of sets with Ferrograph recorders, and it is common to find Reslos in a Ferrograph box, usually with a matching transformer.

Update January 2015: Here is one more for the collection - a rather scruffy Philips badged Reslo RV seen on eBay.

Reslo Beebs in Organ Action

Organist Andy Wright used a pair of our Xaudia Reslo 'Beeb' ribbon microphones to record his organ playing at St Peter and St Paul Church, Kimpton, Hertfordshire.

Reslos at St Peter and St Paul Church, Kimpton

He kindly sent in this brilliant photo, and an .mp3 file too so that we can hear how it sounds! 

Organ recording with Beeb Reslos - Andy Wright.


(Or download the file)

The recording was made with the mics plugged straight into a Tascam DR100 mk 2 and recorded in wav mode, then compressed to mp3 in Soundforge.

In the eighties and early nineties Hyperion Records used the organ to record classical music, including string quartets, piano solo and the Kings Consort doing The Four Seasons. Eventually Luton Airport, about 8 miles away, got too busy!

The Reslo RB mics are perhaps most famous for being used by the Beatles in their Cavern Club days. As a young photographer, Andy was assigned to one of their early gigs, and here are some of those photos at the Daily Mail website.

One of Andy's photos of the Beatles

You can see more of Andy's photos at his website.

Reslo MR1 ribbon mic (MOTM)

The MR1 was an attempt by Reslosound to re-invigorate the classic RB model for a 1970s market, whilst trimming down the cost of manufacturing parts and assembly.

Reslo MR1 and RB models

The MR1 (left) has the same format as the RB, with the ribbon element and magnets housed in a tilting head attached to a cylindrical body that contains the transformer. The grills are now flat, rather than domed, and the custom pivot screw is replaced with a standard hex socket bolt.

Reslo MR1 and RB

The MR1 still usesd Reslo's custom 3-pin connector, and still makes ground contact through the body only. One assumes that this was to ensure backward compatibility with their older mics and cables, but it seems like madness  that they did not take the opportunity to switch to using XLR connectors, which were very well established by this time.

The classic stamped brass badge on the RB is replaced by a printed foil sticker that hides the join between the barrel of the mic and the cast base of the pivoting head. The sticker shouts 'Reslo MR1' - note that it no longer says 'Reslosound' - in a very trendy 1970's style font, with fattened letters typical of the era. I am also 1970s vintage, and the label reminds me of watching programmes like Magpie on TV in my childhood!

Magpie - classic 70s font!

The ribbon and motor assembly (top in the picture below) is exactly the same as the RB, but the transformer is smaller. Over time, better understanding gave rise to alloys with higher magnetic permeability, enabling smaller transformers to be made with the same inductance properties.  The RB mics used a EE24/25 size core (pictured below the motor). The MR1 has a narrower body and a smaller transformer marked 4414.

Top to bottom... Reslo MR1 motor,  transformers from RB, MR1 and Xaudia

Xaudia, as you might expect, make a suitable replacement transformer (bottom) for upgrade and impedance matching duties. ;)

Compared to the RB, I see very few MR1s, and can only conclude that they were not a great success. By the 1970s, good dynamic mics were becoming the first choice for home recording, and professional recording studios would probably favour condenser microphones for many applications. Reslosound Ltd. disappeared sometime in the 1970s, and this must have been one of the last models that they produced.

Reslo RV and UR microphone variations

Reslo RV ribbon velocity microphone.

The RV was one of Reslo's earliest ribbon microphones - possibly their first production model, although I am not sure if the UR series came before or after. They share parts so it is hard to pin down which one came first.

Inside Reslo RV mics

The two mics shown have the same frame for the ribbon, but the magnets are very different. I believe the mic on the right to be the earliest RV design, or at least the earliest I have come across, and it uses a single cast magnet with quite a complex shape.

Reslo RV magnets

The mic on the left uses two simple horseshoe magnets at the top and bottom, attached to a pair of metal pole pieces, and this really sets the style for all subsequent Reslo ribbons - later models have three magnets but use a similar layout.

The UR model has a similar construction but has a rear mounted transformer. This is effectively blocking the pickup from the rear of the mic, giving it a more cardioid pickup pattern. It seems likely that 'UR' stands for Unidirectional Ribbon, although I have not seen any documentation to support this.

Reslo UR magnets and rear-mounted transformer

But the story doesn't end there. Many of the RVs that I have worked on have a later, smaller motor which is essentially the same as found in the RB model. Keeping common parts with the later models must have kept costs down.

Reslo RV mics with different motors.

Until very recently I had only ever seen 30 ohm versions of the RV and had assumed that they were all low impedance. However, the one on the left, which came in recently, has a high impedance transformer, and measures around 6.5K ohms with the original ribbon.

Reslo mics don't have serial numbers or dates on them, so it is hard to make a definitive time line for the development, and always if you have any further information we would love to hear from you.

Short, stubby and dynamic - The Reslo PGD

Reslos are best known for their ribbon mics, but they made some dynamics too. 

Short, stubby and dynamic - The Reslo PGD

This early model is labeled 'Dynamic - PGD', which one assumes stands for Pressure Gradient Dynamic. It proudly says 'Reslo', on the badge -  the later RB mics were mostly labeled 'Reslosound Ltd'.

The PGD appears to be made of leftover parts from the RV ribbon mics. The base of the mic is the same, complete with swivel mechanism, and the grill looks like a cut down version of the RB too. As usual it uses the annoying Reslo plug.

The head on the RGB could be tilted for best pickup of sound.

There is space in the base of the mic for an output transformer, although this 30 ohm example doesn't need one. I don't yet know if they were produced with other output impedances, but it would not be surprising, as later models like this pencil mic came with switchable outputs.

Reslo PGD - aluminium diaphragm

Like many early dynamics, it has a pressed aluminium diaphragm, which is heavy and stiff compared to later polymer film designs. Consequently has a quite lumpy response. Here is a frequency plot for one mic - other examples may differ!

Frequency sweep for Reslo PGD mic.

Thanks to Sean Davenport.