Elizabethan LZ-34 modification... - UK Vintage Radio Repair and Restoration Discussion Forum

Paulus.d · 15th Mar 2011, 7:20 pm

Hiya,

How easy would it be to modify an LZ-34 to have an amp input for a record deck so you are using the amp to play records?

I presume it's somewhere on the Play/rec switch?

Would there be a way to perminentely modify an LZ-34 into a nice valve record player if you had a nice Collaro conquest or BSR deck?

It's just I have this wanting to have a valve portable record player again after so many years and the Ebay prices for these things is through the roof, plus some fun actually building it yourself....either that or finding someone locally who wants to trade?

Regards Paul

AndiiT · 15th Mar 2011, 7:36 pm

Hi,
I wouldn't go as far as modifying the LZ-34 into a complete record player but if you just require an input for a crystal or ceramic cartridge from an external record deck, such as a Collaro Conquest, BSR UA series or one of the Garrard SP or AT series decks, a screened lead connected across the outer two terminals of the Volume/Record level control (with the screen to the ground connection) of the tape recorder should allow the recorders amplifier to be used as a "direct amplifier" without having to mess around with the record/play switching.

Regards
Andrew

Ed_Dinning · 15th Mar 2011, 10:15 pm

Hi Paul, as Andy says, it should be quite simple; do you have access to the circuit diagram?

Ed

Paulus.d · 15th Mar 2011, 11:14 pm

Yes, I'm sure I have...

Yeah, I don't really want to strip it and rebuild into a record player but a handy input socket to plug a nice stereo cart, wired for mono would a bonus!

Regards Paul

Paulus.d · 15th Mar 2011, 11:16 pm

I suppose though, a valve amp could be constructed and a case made if I wanted to be a bit more hands on!!

peter_sol · 16th Mar 2011, 12:30 pm

The input sockes will be MIC for microphone and the other will be marked AUX or Radio or Gram. Use the second socket and that will already be connected to the input volume control as already mentioned.

AndiiT · 16th Mar 2011, 8:44 pm

Hi,
The LZ-34 probably uses the output valve to double up as the Bias/Erase Oscillator during record mode so the problem with using the Radio/Gram socket as it stands is that the signal will only be fed to the recorders amplifier during record mode at which time the recorders speaker will be muted due to the dual use of the output valve.
Additionally, whilst not being too much of a technical problem, the Radio/Gram input will probably be fed into the recorders amplifier one stage before the volume/record level control, usually from one half of an ECC83 or the triode section of an ECL86.

By wiring direct to the volume control a signal can be fed directly to the recorders amplifier whether in recording or playback mode, this connection can also double up as a low level output for feeding the tape recorders output to an external amplifier or PC sound card if desired.

Regards
Andrew

julie_m · 17th Mar 2011, 12:06 am

Cannibalising an old tape recorder to build an amplifier isn't a bad idea; it'll definitely have a power transformer, because it has to be able to connect to external equipment - even a hand-held, metal-bodied microphone. The valves will have plenty of gain and there should be enough heater power, without the magic eye, for an extra one. But I wouldn't cut up a recorder that was mechanically sound. There are enough out there with failing rubber parts that would be better for recycling.

Paulus.d · 19th Mar 2011, 1:53 pm

Tried the radiogram socket for an audio input, yeah you're right - It records through it but the speaker is muted!

To be honest, I am not going to canabalise this LZ-34 to create a record player - well at least not yet! I am still looking around for a nice Hacker or Bush simlar to the ones I had when I was younger....That sound like a good topic for a post!!!

Regards Paul

15th Mar 2011, 7:20 pm	#1
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Elizabethan LZ-34 modification... Hiya, How easy would it be to modify an LZ-34 to have an amp input for a record deck so you are using the amp to play records? I presume it's somewhere on the Play/rec switch? Would there be a way to perminentely modify an LZ-34 into a nice valve record player if you had a nice Collaro conquest or BSR deck? It's just I have this wanting to have a valve portable record player again after so many years and the Ebay prices for these things is through the roof, plus some fun actually building it yourself....either that or finding someone locally who wants to trade? Regards Paul

15th Mar 2011, 7:36 pm	#2
AndiiT Octode Join Date: Aug 2005 Location: Saltburn-East, Cleveland, UK. Posts: 1,786	Re: Elizabethan LZ-34 modification... Hi, I wouldn't go as far as modifying the LZ-34 into a complete record player but if you just require an input for a crystal or ceramic cartridge from an external record deck, such as a Collaro Conquest, BSR UA series or one of the Garrard SP or AT series decks, a screened lead connected across the outer two terminals of the Volume/Record level control (with the screen to the ground connection) of the tape recorder should allow the recorders amplifier to be used as a "direct amplifier" without having to mess around with the record/play switching. Regards Andrew

15th Mar 2011, 10:15 pm	#3
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Elizabethan LZ-34 modification... Hi Paul, as Andy says, it should be quite simple; do you have access to the circuit diagram? Ed

15th Mar 2011, 11:14 pm	#4
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Elizabethan LZ-34 modification... Yes, I'm sure I have... Yeah, I don't really want to strip it and rebuild into a record player but a handy input socket to plug a nice stereo cart, wired for mono would a bonus! Regards Paul

15th Mar 2011, 11:16 pm	#5
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Elizabethan LZ-34 modification... I suppose though, a valve amp could be constructed and a case made if I wanted to be a bit more hands on!!

16th Mar 2011, 12:30 pm	#6
peter_sol Octode Join Date: Aug 2003 Location: Welwyn Garden City, Herts. UK. Posts: 1,906	Re: Elizabethan LZ-34 modification... The input sockes will be MIC for microphone and the other will be marked AUX or Radio or Gram. Use the second socket and that will already be connected to the input volume control as already mentioned.

16th Mar 2011, 8:44 pm	#7
AndiiT Octode Join Date: Aug 2005 Location: Saltburn-East, Cleveland, UK. Posts: 1,786	Re: Elizabethan LZ-34 modification... Hi, The LZ-34 probably uses the output valve to double up as the Bias/Erase Oscillator during record mode so the problem with using the Radio/Gram socket as it stands is that the signal will only be fed to the recorders amplifier during record mode at which time the recorders speaker will be muted due to the dual use of the output valve. Additionally, whilst not being too much of a technical problem, the Radio/Gram input will probably be fed into the recorders amplifier one stage before the volume/record level control, usually from one half of an ECC83 or the triode section of an ECL86. By wiring direct to the volume control a signal can be fed directly to the recorders amplifier whether in recording or playback mode, this connection can also double up as a low level output for feeding the tape recorders output to an external amplifier or PC sound card if desired. Regards Andrew

17th Mar 2011, 12:06 am	#8
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Elizabethan LZ-34 modification... Cannibalising an old tape recorder to build an amplifier isn't a bad idea; it'll definitely have a power transformer, because it has to be able to connect to external equipment - even a hand-held, metal-bodied microphone. The valves will have plenty of gain and there should be enough heater power, without the magic eye, for an extra one. But I wouldn't cut up a recorder that was mechanically sound. There are enough out there with failing rubber parts that would be better for recycling. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

19th Mar 2011, 1:53 pm	#9
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Elizabethan LZ-34 modification... Tried the radiogram socket for an audio input, yeah you're right - It records through it but the speaker is muted! To be honest, I am not going to canabalise this LZ-34 to create a record player - well at least not yet! I am still looking around for a nice Hacker or Bush simlar to the ones I had when I was younger....That sound like a good topic for a post!!! Regards Paul